Kōken Yasaka

is a third-year student formerly from Daten High School. He is a former member of the Fallen Angels and currently holds the position of Number 1.

Appearance
Yasaka is a tall, lean-built man with dark hair with dark eyes.

His hair is neck-length and slicked back. He also has thin eyebrows, thick sideburns, and a developing beard growing around his face.

However, sometime after his first day at Ishiyama High School, his facial stubble developed into a thin beard with a long but thin goatee developing at the peak of his chin, reaching high just below his bottom lip. Yasaka has since shaved his beard, leaving behind the goatee, and his sideburns have grown to the point where they now curve inward towards his cheeks.

He wears a dark, leather jacket left open with the sleeves rolled-up and his collar upturned. His jacket contains two breast pockets, one on either side of his chest. It contains numerous stud-like adornments on the exterior which is particularly notable on the collar and lapels of the jacket.

Underneath, Yasaka wears one of his V-neck shirts which are either dark with a light-colored neckline or simply light-colored overall. He has dark, leather pants. He also has dark ankle-high boots with light-colored soles and a similarly-colored patch running down the middle of his boots, moreover with dark threads intersecting them. Yasaka appears to wear dark gloves to compliment his thug-like outfit. However, Yasaka has once worn the standard uniform for Ishiyama with a regular light-colored shirt underneath and without his dark gloves.

Yasaka often adorns himself with accessories. He always wears dark sunglasses which are typically adorned over his forehead, just above his hairline. Both of his ears are pierced with two dark studs on each Yasaka has also worn a dark, rope-like necklace once around his neck.

He also has an inverted diamond-shaped scar on his right cheek, directly below his right eye. Yasaka gained this scar sometime after he first started attending Ishiyama High School as it was not present during his first arrival.

Personality
Yasaka has a very calm, level-headed personality. He reacts calmly in many situations, even when it is one that would normally alert a majority of other people, such as when Oga first reveals himself to the members of the Fallen Angels. Yasaka's calm demeanor extends to even the most incredulous situations, such as when he discovers that he has eaten a person's "soul", something he quickly shrugs off afterwards.

Additionally, Yasaka has an evident fondness for smoking.

History
Yasaka originally attended Daten High School until he transferred over to Ishiyama High School.

Return to Ishiyama High School Arc
Yasaka arrives at Ishiyama High School on the first day of the new semester. He stands behind the school's entrance, smoking a cigarette, and telling himself about how every newcomer at the high school wants to reign at the top of the student hierarchy.

Several days later, Yasaka sits in an office-like room inside a building with two others. Outside, Himekawa waits to begin his fight with Tōjō. One of the people with Yasaka ask him whether he actually can trust someone with as shady of a history as Himekawa. While holding up his left hand, Yasaka states that he cannot but trails off as he prospers the idea of Himekawa taking down an opponent as powerful as Tōjō. He later smiles shortly after the event occurs.

Yasaka is then seen lounging against a sofa at the head of a pool table, crossing his legs and extending his arms out. He, alongside several of the other Fallen Angels, wait for Himekawa to arrive, which he eventually does. Yasaka then calls for Takamiya to start talking and sits in while the first-year speaks, grunting noticeably from afar. Afterwards, he notices a commotion outside the classroom and watches, unfazed, as Oga appears. Yasaka takes no action whatsoever during Oga's brief moment with them and also says nothing when Himekawa concludes what they should do against him.

The Fallen Angels members later head to the Ishiyama campus where most of the members remain inside the cafeteria, including Yasaka. There, they all dine to Suzune's cooking while the rest of their gang is away. When Ogata incorrectly pronounces Furuichi's name, Yasaka points this out but ends up mispronouncing it himself.

The meal is then unexpectedly interrupted after four mysterious meat-like pieces burst through the windows and float before each of them; surprised, Yasaka contemplates what it is. Udagawa tells the delinquents to eat it as it is a present from Takamiya. Yasaka and the others reluctantly eat their shares; afterwards, they feel an immense amount of power surge through their bodies, though Yasaka makes no verbal comment about the matter.

Later, Yasaka and Sally take a walk in the hallways of the school where they are later approached by Hidetora Tōjō, who is apparently looking for a person named Furuichi, though Yasaka is unable to remember the person's name.

Tōjō quickly attacks Yasaka but the latter blocks his attack. Then, while the other is distracted, Yasaka restrains Tōjō's arms so that he would not be able to move, therefore allowing Sally to punch him; before the second-year could strike, he is scolded by Yasaka for the weak punches that he threw earlier on. However, he then releases Tōjō at the request of his fellow Fallen Angels member.

Before they commence their one-on-one match, Yasaka remarks on Tōjō's loss to Himekawa, which actually disappointed some of the other members, and he then tells Tōjō that he should not feel confident about possibly winning against Sally. Afterwards, Tōjō explains about the extensive training that he had undergone since then. Sally suddenly yells aloud which startles the two third-years who quickly discover that Sally has actually eaten part of Takayuki Furuichi's "soul"; Yasaka realizes that it is the "dessert" sent from Takamiya earlier on.

Yasaka then proceeds to observe the two as they fight each other, making a soft grunt at Sally's apparent victory, though he then shows surprise when Tōjō actually defeats him. He looks on at Tōjō who now reveals a King's Crest marked under his left shoulder, causing Yasaka to open his mouth and allow the part of Furuichi inside him to make another punchline. Afterwards, he then notices the number near Tōjō's King's Crest which is the number 4. The sight puzzles Yasaka who believes that only Hajime Kanzaki and Aoi Kunieda should be the only other members of Oga's court; with that in mind, he wonders who the number 3 could be.

He is then momentarily distracted by a commotion outside until he then returns his focus back to Tōjō, who now wants to fight against him.

Afterwards, both third-years then have their fight with each other; after a bloody battle, which leaves both heavily bruised, Yasaka stands victorious. While he takes another smoke, Yasaka glances back at Tōjō's lifeless body on the ground near him. He continues smoking when he suddenly senses Tōjō rise up from the ground; knowing of his intentions, Yasaka tells Tōjō that he has lost and that he needs to give up. Yasaka adds further insult by remarking how Tōjō's loss is because of Oga who ended up leaving him without a King's Crest to use for battle.

Afterwards, Yasaka attempts to ultimately bring Tōjō down but finds that he is unable to do so. As he contemplates on the fact, he is suddenly struck with a powerful punch, forcing him on his knees. Shocked, he struggles to keep his mouth closed but ends up opening it anyways after hearing Tōjō's following comment.

Sally Night
Yasaka shares a friendly relationship with fellow member, Sally Night, similarly to that of actual brothers, as he is able joke freely with the younger individual, such as making a casual comment about his punching technique. He holds Sally's strength in a certain regard as he knows that Sally is the No. 5 of the Fallen Angels; attributing to this fact, he is also considerate of Sally's own opinions, having once allowed Sally to fight alone against Hidetora Tōjō at the latter's behest. Yasaka furthermore showed surprise when Tōjō was actually able to defeat Sally.

Quotes

 * (To himself): "There's only one seat at the top of Ishiyama... and all the up-and-coming powers want it."

Trivia

 * Although Yasaka is the most powerful member of the Fallen Angels after Takamiya, making him the first-year's strongest subordinate, he is often mistaken to be Takamiya himself, proven in many other delinquents' own depictions of the former head.