Kinichi first physically appeared in the Epilogue of Vol.3 at the end when he requested Kinji to help him kill Aria. Kinji refused and ended pointing his gun to Kana which was something he had not expected. He later appears in Vol. 4 sparring Aria, It is revealed that Aria was chose by "The Professor" the leader of IU to be his successor. Kana's plan was to kill Aria which will led the organization into chaos as he was certain that Aria would not be able to reject his offer. However, Kinji defeats Kana and proves him to believe that Kinji's feelings for Aria are strong enough to destroy IU in a different manner and aids Kinji and Shirayuki in defeating Patra. Afterwards, he is shot through the heart by "The Professor " who is revealed to be Sherlock Holmes, who's life was extended through the use of Irokane. Sherlock takes Aria, causing Kinji to enter Hysteria Berserk. Meanwhile, Patra, who is in love with Kinichi, attempts to heal him, but he brushes off her attempts. On his deathbed, Kinichi enters Hysteria Agonizante and tells Kinji to help him chase down Sherlock and arrest him, as now is the perfect time because Sherlock had just kidnapped a minor in front of their eyes. The two brothers have a massive gunfight with Sherlock on top of the IU submarine, stated by Kinji to be the first ever true battle of "Bullet Contact". However, Sherlock uses Vlad's technique "Wallachia's Magic Flute" which is designed to disable Hysteria Mode. Kinji having faced the technique before is able to defend himself and maintain his HSS but Kinichi's HSS is disabled and he is shot in the heart again while defending Kinji. He tells Kinji to chase Sherlock and arrest him.
Despite being shot through the heart twice, Patra is able to heal him and the two of them are last seen embracing while Kinji and Aria float down from the sky after Sherlock launches himself into the sky using an ICBM.
In Volume 8, Kana chooses to be "Unaffiliated" when choosing sides between Deen and Grenada. He was studying at Rome Butei High in the Assault Department.
During the events of Volume 11, it was revealed G III had visited Kana prior to coming back to Tokyo to confront Team Baskerville. Kana witnessed the battle between Team Baskerville (including Jeanne d'Arc and Hilda) and G III (Kinzou Tohyama) and Kaname Tohyama, where he refused to get involve and only observe the battle from a far. After, Kinji and G III left on the sea-plane Galleon to fight, Kana would heal the injuries G III inflicted on Kaname for defying him.