Chougasaki is soft spoken, but despite his manner of speech and dress, is still as depraved as the other Minuses. He breaks Kumagawa's arm without hesitation when first introduced, and agrees with Shibuki Shibushi's reasoning when she attacks Hansode Shiranui, and even joins her in her assault, commenting that those who talk big should not complain. Maguro Kurokami claims Chougasaki is even scarier than Kumagawa. Because of his Minus, Chougasaki is the most rational member of Class -13, and has not grown twisted like the other students, as all trauma and stress has been pushed away. Kumagawa claims Chougasaki's rationality is both the good point and the weakness of his Minus. Despite his usually calm demeanor, Chougasaki harbors an intense hatred for games; becoming infuriated when Kumagawa implies he cannot tell the difference between the three-dimensional world of real life and the two-dimensional world of games, and when Kuudou Hinokage makes comparisons between real life and a video game. After becoming enraged, Chougasaki's personality becomes noticeably nastier. Chougasaki has a strange relationship with fellow Minus Shibushi; the two have been together for ten years, though Shibushi claims don't match. Instead, Shibushi remains with Chougasaki because she does not want to die. Along with Shibushi, he is extremely loyal to Kumagawa, believing him an even greater Minus than he is himself. This loyalty remains even after Kumagawa is defeated and reformed. Chougasaki has a tendency to label the results of his Minus as "an unexpected accident".
Chougasaki has blue eyes and turquoise colored hair. His hair hangs forward, though a strand sticks up from the back. When infuriated, Chougasaki's hair style changes, becoming lighter in color and slicked back from his face, as opposed to his usual style. As a transfer student like the rest of Class -13, Chougasaki does not wear the uniform of Hakoniwa Academy. Instead, he wears an elegant black suit, a red tie, white gloves, and a monocle.
At age six, Chougasaki wore a dark-colored, long-sleeved collared shirt with white shorts. He also wore a pair or round glasses.
Chougasaki has no memorable past; he discovered his ability as a child. Using it, he would push away all the injuries, problems, bad memories, and pain in his heart onto his surroundings, leaving everyone around him to suffer through his pain. Doing this caused his family to leave him, so from a young age he lived on his own. He had doubts about living this way and felt guilty over pushing his trauma onto other people, but he soon pushed those feelings away as well and forgot about them. He continued to live his life, believing that living without any sad or painful memories he could become happier than anyone else. He continued to push them away until there was essentially nothing left. Chougasaki and Shibushi met as children while waiting to be examined at Hakoniwa General Hospital; Chougasaki was six and Shibushi was five. Annoyed by the noise Chougasaki was making by pressing the buttons of his DS, Shibushi assaulted him with her bat. He fell to the floor but instantly recovered, taking no damage, and apologized to Shibushi. He was then led to his examination room, but not before politely excusing himself and calling her pretty. Chougasaki and Shibushi were the last Abnormals to come to the hospital Hitomi Hitoyoshi worked at, though they were not brought in until after she had left. The two became famous for destroying the facility without leaving a trace of it behind. According to Hitomi, this was a feat no other Abnormals could have accomplished.
Kumagawa Incident Arc
Chougasaki and Shibushi interrupt Kumagawa's fight with Hinokage, breaking both of their senior's arms. After Kumagawa restores himself, the three face Hinokage together. The three put some desks together and get out their food to have an executives' meeting. Chougasaki is inspired by Kumagawa, and decides to follow him from the bottom of his heart. When Shiranui arrives, Chougasaki attacks her for talking big after showing up late. He is surprised to see Shiranui unharmed. Hearing Shiranui's plan, Chougasaki states it sounds like something straight out of hell. One week later, at the end of the semester, Chougasaki and the other students of Class -13 show up with Kumagawa as part of his new Student Council. After Medaka Kurokami declares a Student Council battle with Kumagawa, the students of Class -13 decide on who will fight first. They are surprised that Kumagawa wants to fight in the General Affairs Manager's Battle. On July twenty-fifth, during the General Affairs Manager's Battle, Kumagawa explains the absence of the other Minuses; they have gone to the beach to enjoy their summer holidays. This however is revealed to be a ruse; Chougasaki and the other Minuses attack the Student Council during their Devilize Training. Waiting outside Class -13's classroom, the other Minuses discuss Youka Naze. Chougasaki and Mukae Emukae observe Shibushi's confrontation with Naze. After their failure to recruit Naze, Chougasaki and Kumagawa discuss the upcoming Secretary's Battle.
One week later, on the first of August, the opposing Student Councils meet for the Secretary's Battle. After Shibushi makes her choice, the group moves to the stage of the battle, a freezer in the school's canteen. When Kumagawa offers Class -13's surrender if Shibushi loses, Chougasaki voices his complaints. Chougasaki questions Naze as to how she could have prepared for the battle beforehand. Chougasaki explains the true nature of Scar Dead. He assures Emukae not to worry about Shibushi losing, as her Minus can also reopen mental wounds. Chougasaki watches on as Naze breaks down. He is surprised when Medaka uses Kumagawa's head to break open the freezer's window. As Shibushi struggles against Naze's Ice Fire, Chougasaki tells her to use mental damage. As Shibushi's fully powered Scar Dead damages the spectators and even the building, Chougasaki remembers the skill from ten years previous. He is surprised by the range of Ice Fire. The other Minuses chose to follow Kumagawa's lead, and make to leave the academy, Chougasaki carrying Shibushi on his back. He is impressed by Kumagawa's ploy to break Medaka's will. On August eighth, the opposing Student Councils meet at the academy's botanical garden for the Treasurer's Battle. The nonparticipants watch the battle on several computer screens. Chougasaki looks to Medaka after Kumagawa finishes explaining their mutual history at Hakobune Middle School. Chougasaki watches the monitors display Kumagawa's breakdown over Emukae. He and Shibushi run up to Kumagawa, telling him to pull himself together. Kumagawa tells Chougasaki to take over Class -13, as he will need to retrieve his original Minus. The two help Kumagawa leave. In their classroom, Kumagawa asks Chougasaki to kill him so that he can retrieve his original Minus. Chougasaki refuses, but Kumagawa provokes him into a rage. Kumagawa attacks with a screw, only for Chougasaki to stop him in his tracks with Encounter. Chougasaki defeats Kumagawa, then kills him by crushing his head.
On August fifteenth, Chougasaki prepares to face Medaka in the Vice-President's Battle. They are interrupted by the arrival of Hinokage, who offers to fight Chougasaki in Medaka's place. When Tokemichi Choujabaru considers letting Hinokage participate in the Vice-President's Battle, Chougasaki prompts him to check with his superiors. Choujabaru does so, telling Chougasaki to select a card in the interim. The group moves to an under construction building for the Vice-President's Battle, "Dropping Mad Dog". When Naze realizes that the stage provides several disadvantages to Hinokage because of his size, Chougasaki admits that he researched and chose the battle on purpose. Hinokage interrupts Chougasaki's gloating with an attack faster than he can see, knocking the junior back. As Hinokage introduces his new Abnormality as Theme Song, Chougasaki tells him it will be his requiem. Hinokage attacks relentlessly, but Chougasaki is unharmed and unconcerned, even going so far as to put his hands in his pockets. He mocks Hinokage's desire for understanding, only to become annoyed by Hinokage's optimism. As Hinokage continues to attack him, Chougasaki uses Encounter to redirect the damage to the building's supports. With the strength of two hundred and fifteen of Hinokage's punches, Chougasaki brings the construct collapsing to the ground. He is surprised to see Hinokage survived, and even managed to keep himself from being disqualified. Hinokage creates several copies of himself and charges Chougasaki, attacking from all directions. Chougasaki is unfazed, and redirects the damage to Medaka. He is amazed to see Medaka can still move, but noticing that Hinokage's Theme Song has worn off, Chougasaki starts to gloat. Chougasaki begins to panic as Hinokage rouses, not understanding why he continues to fight without his Abnormalities. With a roar, Hinokage destroys the platform he and Chougasaki are on top of. Hinokage rides Chougasaki's body as they fall, crash landing on top of him. Because Chougasaki's body touched the ground and Hinokage's body did not, Choujabaru declares Hinokage the winner.
Afterward, Chougasaki mockingly congratulates Hinokage on his victory, pointing out that Hinokage is near death, while Chougasaki himself is unhurt and unreformed. He and Shibushi are unconcerned as the student body boos them. He is surprised by Kumagawa's arrival. On August twenty-second, the Student Council and Class -13 gather for the final battle. Chougasaki and the other members of Class -13 climb onto the rooftop Medaka and Kumagawa are fighting on. Chougasaki watches as the battle devolves into a punching fest. He is surprised to hear that the crowd cheering for Medaka are all her enemies. After the battle ends, Chougasaki and Shibushi approach the fallen Kumagawa. The pair promise to stick with him, Chougasaki noting that, if Kumagawa can be reformed, there is no reason they all cannot be. Helping him up on their shoulders, the three prepare to leave the academy. They are stopped by Medaka, who offers Kumagawa the position of vice-president.
Kurokami Medaka's Successor Arc
Unknown Shiranui Arc
At the end of the academic year, Chougasaki is among the students present at the Hakoniwa Academy graduation ceremony. Listening to Kumagawa's speech, he smiles at its conclusion.
Bouquet Toss To The Future Arc
Chougasaki and Shibushi await Medaka in the Ghost Babel, to challenge her as part of the 100 Flowers Run. When she comes to them before Kumagawa, the pair ask her to tell him that they fought with the intent to win. His message to Medaka is the acknowledgement of the Minuses' debt to her.
Ten years later, Chougasaki's and Shibushi's whereabouts are unknown.
Superhuman Physiology: Chougasaki has displayed great physical strength, effortless breaking one of Kumagawa's arms on one occasion, and crushing Kumagawa's head and a large section of floor on another. Hitomi claims that it is because of his and Shibushi's great power that Kumagawa has been able to launch his plans before the rest of Class -13 arrived at the school.
Encounter (不慮の事故, Enkauntā): Chougasaki's Minus allows him to push away all damage inflicted on him, including all physical, emotional, and mental damage, elsewhere. No matter how fast or numerous the attacks, he will take no damage from any assault. The location is specified by him and can range from structures to other people. Chougasaki claims his Minus cannot be rationalized; even if there is no opening, Encounter will still push any damage away from Chougasaki. Though only seen once, Chougasaki can also create a defensive barrier that stops an opponent's attack in its tracks. Encounter can even push away Chougasaki's own death. Hinokage labels Chougasaki's Encounter as more complete than Medaka's The End and more disgusting than Kumagawa's All Fiction. However, Chougasaki was affected by Shibushi's Scar Dead, the skill that reopens old wounds, suggesting that he has suffered injury at some point in his lifetime.
- When translated from kanji, Encounter means Freak Accident.
- Chougasaki was voted the fourteenth most popular character in the series in the third popularity poll with 169 votes.
- Chougasaki was voted the fourteenth most popular character in the series in the second popularity poll with 218 votes.