Adolf K. Weismann is the Silver King, formerly a researcher in Germany who experimented with the effects of the Dresden Slate. He was ejected from his original body by the Colorless King and had since inhabited the body of a teenage boy, where after becoming amnesiac, Weismann assumed a new identity, Yashiro Isana
Weismann was a tall, youthful-looking man with knee-length, silver hair and gray eyes. His hair was straight and a single lock of it fell to the left side of his face, splitting into two parts. His attire was formal-themed. Weismann wore an open, long-sleeved dark green trench coat with rolled-up sleeves and four buttons outlining each storm patch on the fronts of the clothing. The buttons and the lining found on the sleeves and storm patches were yellowish green. Underneath his trench coat was a white shirt with a ruffled collar and center front. Weismann wore dark green pants to match with his trench coat and white shoes for his shirt.
Several decades prior, Weismann's hair was shoulder-length and flipped outwards. His bangs were parted to frame both sides of his face. He wore the general uniform of German soldiers with a laboratory coat over it, additionally with a red and black armband over his left arm. Underneath his uniform was a yellow shirt and a green necktie.
After he came to possess a new body due, and since became Yashiro Isana, he then came to appear as a male teenager of average height with messy, white hair and amber-colored eyes. Initially, he wore a dark blue Japanese school uniform over a long-sleeved white shirt, with a closed high-collared jacket and loosened pants topped with brown shoes. However, after unofficially enrolling in Ashinaka High School, he was given a new uniform to suit the regular look of the male students on the campus. It was composed of a long-sleeved white shirt with a red ribbon tied around his neck, rather than a normal necktie or bowtie, with a black jacket on top, in which it was also high-collared and with the golden pin of Ashinaka High School attached to the outer left side. Yashiro wore matching pants underneath, rolled up above his ankles. He retained his brown shoes but wore no socks with them.
Sometime after becoming a high school student, Yashiro gained possession of a Japanese red parasol. The stick was a light brown and at the top, circling the end, there was a distinctive cross-like green pattern outlined with a golden trim
During his years as a researcher, Weismann was very optimistic and encouraging of his experiments, believing that he and his sister's research would bring eventual happiness to the rest of the world. Despite his friendly attitude towards military officers such as Daikaku Kokujōji, Weismann opposed war and avoided it as much as he possibly can, even escaping from the world in the Himmelreich following what he believed was its end.
He retained most of his original personality after assuming a new body, such as being charismatic and very carefree. Yashiro is able to get along with almost everyone, whether it is people or animals or robots. He is kind hearted and very open about his feelings to everyone. He had since developed something of a trickster side, such as telling Kuroh that he had a younger sister just so he can pull another stunt that made it appear that he'd run away. For reasons such as that, Yashiro has also been called insincere or even a liar.
While Weismann was conducting research on the Dresden Slate in the titular city, Japanese Lieutenant Daikaku Kokujōji came to witness their experiments in the final year of World War II. Weismann used an experiment involving albino mice that triggered the effects of the Slate, thus creating potent Aura in the mice, with specific individuals developing their own Sword of Damocles.
When the Lieutenant suggested using such power on humans to create powerful armies, Weismann interjected, believing that the Aura could be used to bring happiness instead. He expressed his thoughts on the matter to his sister Claudia who punished him for being too blatant in the presence of the Lieutenant. However, when the Japanese officer admitted to not understanding most of what they are saying, Weismann and his sister laughed.
One day, Dresden was bombed and left in complete ruins afterwards. With his own Aura shrouding over his body and a Sword of Damocles hovering over his head, Weismann tearfully cradled his dead sister in his arms. As he sobbed for her, he noticed the Lieutenant running over to him and tried to explain what had happened.
In April of the same year, Weismann met with the Lieutenant in open fields. He claimed that the war was over to him and bid farewell before moving forward to board the Himmelreich.
Several years later, Weismann was visited by the Colorless King and they had a small, initially friendly conversation with one another. Weismann reminded the newly-made King that he no longer associates himself with the outside world. To his surprise, he is then knocked unconscious, later to awaken in a new body. Through unknown circumstances, he was pushed to the edge of an open blimp. He barely manages to hold onto the aircraft and tries clinging on for his life. The Colorless King, who had since inhabited Weismann's original body, looked down upon him and kicked him out, causing Yashiro to plummet several hundred feet into an old shed.
He eventually crashed into an island just outside Shizume City, specifically on the campus of Ashinaka High School. He broke through the roof of the school's gymnasium and landed on a mattress-like object, completely unharmed. He rose from it and noticed a pink cat near him in the dark, hissing in annoyance. Yashiro apologized to the cat and it quickly became attached to him, hopping on his lap so that Yashiro can hold and stroke its fur. The door to outside then opened and a teenage girl named Kukuri Yukizome entered the building. Yashiro is soon discovered and inquired about his name.
He notices a poster for Ashinaka's upcoming festival and hesitantly said that he was Yashiro Isana. Kukuri slowly starts to recognize Yashiro as one of her classmates and accuses him of slacking off during the production for the school festival. Subsequently, when asked about the hole he made in the roof, he stated that he did not know what happened. However, Kukuri did not believe him.
Since that night, Yashiro was led to believe that he was a high school student, and that he'd left his parents to go study at Ashinaka High School.
After getting rice for his lunch, Yashiro asks several of his classmates to share their lunch with him, to which they oblige. Afterwards, he goes across campus trying to get more people to share, even attempting to sneak food from the cafeteria. Once his bento is completely filled up, Yashiro heads to the rooftop of one of the school's buildings to eat his lunch. The pink cat from before accompanies him and also eats his meals. Yashiro lazily stretches his arms and says that Japan is a great place. He then takes a quick nap.
Yashiro then returns to class with the little cat. He notices that everyone is not studying and wonders why, only to learn that they're preparing for the school festival. Kukuri asks for someone to help run errands for the school council and Yashiro is chosen to do so. She attempts to send him a list through their PDAs, but Yashiro cannot find his, so she writes it down. Kukuri also tells him that he needs to find it otherwise he can't leave campus, but he tells her not to worry, taking the note with him. Yashiro finds a key to one of the doors inside campus and uses it to maneuver through security, rather than having to leave using a PDA. He then walks to the city on the bridge.
While in the city, he manages to purchase the items from a local store. While walking out, however, Yashiro is suddenly attacked by a male teenager with a skateboard and a baseball bat, causing him to drop the items and try to run for his life. He runs across town, hopping onto people's vehicles, and even crosses through alleys to get away. He is soon cornered into an alley where a blonde man attacks him with unusual fireballs, which he conjured from the sparks on the cigarettes he's been smoking. Luckily, a long-haired teenager arrives and saves Yashiro from the mysterious people.
The teenager takes Yashiro to the rooftop of another building just near the train station. Yashiro thanks the male and tries to go off on his way, but is prevented from doing so. The teenager introduces himself as Kuroh Yatogami and explains that he is the vassal of the Seventh King, Ichigen Miwa, and that he must also slay the "evil" King. Yashiro is confused by his words. He is even more confused when a video, depicting a man nearly identical to Yashiro, is shown across town through a network hijacking. Kuroh claims that the man in the video is Yashiro himself.
Kuroh adds that under his master's orders, he will take Yashiro's life. Yashiro attempts to run away but is caught by Kuroh's Aura, suspending him in the air. A frightened Yashiro asks if Kuroh will actually kill an innocent man such as himself. He is then dropped but caught in Kuroh's arm. Yashiro continues arguing that he is actually innocent, though he is unable to convince the sword-wielding teenager.
Yashiro seemingly gives up hope resisting and says that Kuroh can do whatever he wants with him as long as he grants him a final request. He is freed from Kuroh's grasp and explains that he has an ill younger sister, who has been hospitalized for most of her life, and that should he die, she would be left without a family. Yashiro asks to write a letter to her so that she will know he's not actually a murderer. Kuroh allows him and then asks to see the letter. Once he does, Yashiro sets off a barrage of flash bombs, using the distraction to seemingly run away. Kuroh runs off after him, though it turns out that Yashiro had quickly disguised himself in an animal suit during the distraction.
Remaining disguised, Yashiro walks around town, completely unaware of the fact that a bounty with his face on it has been sent throughout the city. While walking about, he spots Kuroh again, and quickly retreats. He heads to a rooftop and removes his disguise just before Kuroh and Misaki Yata, the same person who attacked him before, begin their fight. Yashiro tells Kuroh to meet him on the rooftop after he beats up Yata. However, he leaves before the fight ends.
Yashiro returns to his school and sneaks back in the dormitories. He lies on his bed, completely exhausted, with the pink cat resting beside him. Yashiro speaks aloud wondering who the people who attacked him are, as well as how the video came into place. He mutters that it will be hassling and hears someone responding to him. Yashiro turns around to see the pink cat gone, and instead, a naked Human girl instead. Embarrassed, he jumps off his bed and asks who she is, only to be told that she is Neko. Yashiro picks up his jacket and tries handing it to Neko, but she refuses the piece of clothing.
He then hears Kukuri shouting out for him outside and goes to look. Yashiro sees Kuroh next to her, surprising him. Using his ability, Kuroh pulls himself up to Yashiro's dormitory. He draws his sword, attempting to kill him, but is distracted with Neko's nudity whilst before him. Neko takes this opportunity to run away with Yashiro.
While running in the hallways outside his room, Yashiro throws his jacket on Neko, startling her. He then witnesses an abrupt change in the hallways; suddenly, Neko is further away from him. When she exits the building, it reverts to normal, surprising him. Yashiro continues following Neko throughout the campus while additionally avoiding Kuroh, who still strives to kill him. The three-way chase continues for the rest of the day and well into the night, lasting until morning, which by then has left them completely exhausted. They stop in Yashiro's room where everyone begins to show signs of hunger. Yashiro suggests that they end their conflicts to have breakfast and proceeds to make some, though he is unable to figure out how to cook his meals, as well as trying to cook food that appeals to Neko's picky tastes. However, Kuroh ends up cooking for the three of them, and they have breakfast together.
Most of the breakfast was filled with Yashiro asking various sorts of questions, such as having the soy sauce passed to him or what Kuroh's recorder was. However, one of the things he also inquires about are the HOMRA members who chased him before. Though confused throughout the entire explanation, Yashiro does understand that they are Red Clansmen led by the Red King, Mikoto Suoh. He also discovers that the reason they're after him is because of his uncanny resemblance to the man who murdered one of their own members. Kuroh reminds Yashiro that he will kill him once they've finished eating, still believing him to be Tatara Totsuka's murderer. Yashiro denies this claim before he asking for seconds.
Once he's received another full bowl, Yashiro finally asks Kuroh as to why he would want to kill him. He is explained that it is because, as per the murder video, Yashiro is to be the next Colorless King but has been deemed evil; thus, he must be killed by the vassal of his planned predecessor. Yashiro fruitlessly argues further with Kuroh, before he would then ask about the Kings. Yashiro receives another explanation about them, discovering their immense power and authority over Japan. In relation, he hears more about the Red Clan HOMRA and its known Clansmen.
Yashiro, Kuroh and Neko give their thanks for the meal at the end of breakfast. Kuroh proceeds to kill Yashiro though he stops him again, persisting that he is innocent before making a request to have his words be tested. In response, Kuroh has him play a message on his recorder, stating that it has saved his life. Yashiro is relieved to hear that his request will be given. He asks again about Kuroh's recorder; once explained about its history and usage, he comments on how Kuroh is creepy.
The next morning, Yashiro awakens to see that Kuroh has prepared lunch for the day. While ogling the food, he notices a cleaning robot taking away his backback. Yashiro tells it to stop but ends up being mistaken for trash, causing the robot to attack him. During class, instead of studying Yashiro writes down what he would put in his alibi. His teacher comes towards him to ask about Kuroh and Neko, to which he explains that they are supposed to be transfer students. Yashiro eats his lunch with Kuroh and Neko. Throughout most of the break, he attempts to analyze the video of Totsuka's murder, sent by Mishina to Kuroh's cell phone. However, he is unable to identify much from the blurriness in one of the video's screenshots.
Once the lunch break is over, Yashiro goes to change into his Feudal Japan outfit with Kuroh and Neko. While changing, he tells Kuroh that he can prove that he was on campus during that day, specifically within the hour of Totsuka's shooting. The three scavenge for information of the such across campus, from the student council's office to the courtyards near the clock tower. Eventually, Yashiro gets his proof from the teachers' office, where he asks for a log of the number of entries and leaves within school campus. Since his name is not on the list during that day, Yashiro believes that Kuroh can no longer hold it against him.
However, while getting a drink for Neko, Kukuri ends up revealing that he generally just sneaks out of campus, therefore bypassing the school's gates that log everything. As a result, Kuroh deems him insincere and prepares to kill him. Yashiro is protected by Neko, though he pushes her behind him to confront Kuroh himself. Yashiro argues that he can find an alibi that proves he was on campus during December 7–8. Sure enough, Kukuri reveals that she did see him on campus approximately 12:30 AM, proving his case. He celebrates happily and tells Kukuri that he owes her his life.
Yashiro returns to his dormitory, where he comments on how exhausted he is. He goes into his closet to look for a shirt. When he finds one, he horrifically discovers that one of them is bloodstained, just like the ones in the shirt worn by Totsuka's murderer. Though horrified, Yashiro is approached by Neko, who notices that he feels uneasy. He states that she shouldn't worry, though wonders in shock whether he did kill Totsuka.
Yashiro goes with Neko back to his classroom. There, he sits by a desk and wonders about his connection with Totsuka's murder. He is then told to help with the festival production, specifically to run more errands in the city. He has Kuroh and Neko accompany him along the way. The three take the secret exit beyond the school gate, where Yashiro explains that he lost his PDA; therefore, he can't exit normally. While walking along the bridge, Yashiro stops to look out the oceanic horizon.
The three eventually stop at at a restaurant in the city. While he's dazing off, he is reminded by Kuroh that while he may not be proven guilty, there are still many suspicions surrounding him. Yashiro quietly agrees. He then notices a bulletin board next to him with several photos of his classmates on it. Yashiro asks the restaurant owner about them, pointing out that his own photo is nowhere on it.
Once they've all eaten, they head to a store in the city to purchase the fireworks. However, Yashiro's poor penmanship makes it difficult for Kuroh to see what specifically they need to get, and so he decides to call Kukuri; because of this, Neko runs away from them. Yashiro uses Kuroh's cell phone to call Kukuri and ask her about the fireworks; however, Kukuri is unable to recognize him and eventually hangs up. Disheartened, Yashiro explains what happened. He then asks to call his family, wanting to be reassured that there are people who know who he is. Yashiro calls his home but an automatic dial informs him that he cannot contact the number.
Yashiro and Kuroh take a train to a soccer stadium, where Yashiro believes is where his house should be. He admits that it's possible that he may not be who he believes he is, and that Yashiro Isana might not even exist. As tears begin falling down his face, Yashiro wonders whether he actually is a murderer, and asks Kuroh if he still wants to kill him. He readies himself for death. Instead, he is left at a standstill when Kuroh plays a message from his old master. Yashiro wonders what Kuroh means with the message and is told that he will only kill him with certainty. In other words, until he is certain about his actions, he will not kill Yashiro, nor let him give up hope.
A cheered-up Yashiro tries to speak when the headlights around the stadium suddenly flash at his location. Once the brightness has toned down to a more bearable level, members of the Scepter 4 force reveal themselves, telling Yashiro and Kuroh that they will be taken into custody. Yashiro suggests to surrender willingly but is ignored completely. He looks on as Kuroh and the uniformed people prepare for battle, only to soon discover that the terrain has changed completely.
It is then that Neko arrives and takes Yashiro with her towards an exit. They are forced to stop by a blonde-haired woman and eventually her Captain, who dispels the landscape effects that are revealed to be of Neko's doing. Kuroh tells Yashiro and Neko to leave, even clearing an exit for them. Although reluctant, Yashiro leaves with Neko. However, while inside the stadium, he looks back towards Kuroh's location with concern.
Eventually, Yashiro decides to go back to the fields while cloaked in a white light and sees that Kuroh is pinned to the ground. He tells the man over him that he simply cannot let his friends get hurt. He then turns his attention to Kuroh himself. Yashiro apologizes for keeping secrets and exposes a white sphere in the palms of his hands, which hovers over him and transforms into a giant key-like object. His voice suddenly starts to reach out to Kuroh's thoughts. Yashiro exerts a white force from his body and counters against the Scepter 4 Captain's own Aura. Afterwards, he disappears.
Together with Neko, Yashiro leaves the stadium and eventually finds a beaten Kuroh inside an alley. Though worried, he is told not to be. As Kuroh slowly recovers, Yashiro begins to praise Neko for her efforts at the stadium. Eventually, he is told from Kuroh that Neko has the ability to manipulate memories, making Yashiro wonder if she can do anything about his. Kuroh reminds him that if his memories prove that he is actually an evil person, he will be killed, though Yashiro does not mind it. He tells Neko to reveal his true memories to him and she does so; although, Yashiro can only recall the night that he first met Kukuri. Yashiro asks for Neko to try and uncover his past from before then. She manages to show him his innermost memories from the same night: him being pushed off a blimp by a silver-haired man. Shocked, Yashiro wonders who he is.
The following day, Yashiro rests underneath the bridge to Ashinaka High School with Kuroh and Neko. He ponders briefly when Neko happily states that they've "made it back" to their "home". While placing a hand don her head, Yashiro concludes that she is right, since the past few days with the students are real even if his memories of his past are not. He stands up and states that his purpose for returning, which he also just realized, is to engrave the place within his heart. Yashiro then adds that he needs to understand everything that he has been mislead about so that he can restart his life afresh.
Yashiro, Kuroh and Neko later hide themselves in the back of a delivery truck. Using a stolen PDA of one of Scepter 4's members, thanks to Kuroh's help, Yashiro calls Reisi Munakata at 2:00 PM in the afternoon. Yashiro introduces himself and elaborates on why he is forced to contact Munakata through such an unorthodox method. Afterwards, he reveals his suspicions about "a man in an airship" whom he believes is heavily involves in Tatara Totsuka's murder. He later adds that he only knows enough about him from a "crash course". Yashiro listens and appropriately replies to Munakata's following responses. After a bit of talking, he proposes a deal with Munakata, saying that he will freely turn himself in should the "man in the airship" be brought to ground level. Munakata points out the flaws in his plans which Yashiro admits himself soon after. Nonetheless, Munakata agrees to the plan, should Yashiro and his two friends turn themselves in. Yashiro also discovers near the end of the call that the man in the airship is also known as the Silver King.
Sometime after, Kuroh senses the presence of several Scepter 4 members, forcing the three to relocate. Before they do, Yashiro leaves behind the PDA but connects with a circuit board, hoping to mislead their pursuers even while they're gone. Yashiro, Kuroh and Neko then hide within the cargo of a ship down the river. He later exasperates about being hunted down even while speaking to their pursuers' leader. Yashiro speaks with Kuroh and Neko about the next steps to their plan. Then, at Neko's request, he explains his experimenting with the PDA from earlier.
The three later follow Scepter 4 to a local airport during the night; there, they hide themselves near the runways. Yashiro concludes that they have been unable to contact the Silver King and are now using force to get their way. Yashiro, Kuroh and Neko swiftly take out a group of Blue Clansmen and board a helicopter they have planned to use. Then, with Kuroh as the pilot, they join the others in their destination towards the Himmelreich.
On the helicopter, Yashiro asks Kuroh about the Silver King, though he learns very little about him. Kuroh then brings up the issues with their plan but Yashiro is reassured that they will be able to escape with the Silver King swiftly. Then, due to Neko, the helicopter ends up flying uncontrollably towards the engine of the Himmelreich. Afterwards, their crash target suddenly explodes and engulfs in flames, which captivate Yashiro. Another explosion follows when their helicopter hits the Himmelreich directly. Following this, a massive silver-colored light shimmers in place of the explosion caused by both aircrafts.
Luckily, all of them manage to survive the explosion without any injuries. They crash back into Shizume City and eventually learn that HOMRA has recently taken over Ashinaka High School, forcing the three to return. At night, they return to Yashiro's dormitory but discover that it has been completely charred and wrecked.
Yashiro is shocked at the discovery and eventually grows depressed to have returned to a nearly-destroyed home. After some time thinking to himself, he decides that he needs to put aside his quest to remember his former self for the time being, and to clean up the mess left behind. Yashiro asks Kuroh whether they should "seek" out his former master's help. Instead, he is told that they already know what they need to do, and that they should leave so that they can save Kukuri and the other students. Yashiro agrees with Kuroh and they, along with Neko, head out to find Yashiro's former classmates.