Webkaigaku's betrayal led to gyomei's imprisonment and jigoro kuwajima's death, fueling zenitsu's rivalry. Kaigaku became upper rank six of the twelve kizuki,. Webdespite turning into a demon, kaigaku is unable to defeat zenitsu in demon slayer, indicating that the latter is still stronger than the former. However, if kaigaku had. Webit is revealed that jigoro killed himself when he learned that kaigaku had become one of the twelve kizuki, taking the place of daki and gyutaro as the upper. Webwhat follows is kaigaku’s frustrated screams as he disintegrates. Thus, the relationship between zenitsu and kaigaku culminated with the death of the demon.