Chemical Control / bond

Keisuke shows Akira all the tags that he gotten, and stating his desire to see more emotions, particularly the “troubled, agonized, dying” face. They begin to fight, throughout the battle Akira tells Keisuke how he really felt all this time which angers Keisuke even more. Akira gets his weapon knocked out of his hands causing him to get cut and bleed.

Synopsis excerpt via Kitsu.