>>81061030自己管理 is so vague it can mean anything related to your own responsibilities at work, really. Not taking appropriate care of your physical or mental health, making too many mistakes, missing too many meetings/deadlines etc., showing up to work drunk, tax fraud, substance abuse, and so on. Judging by Yagoo's and Rio's statements it doesn't seem like there's a victim party involved (outside of himself and his coworkers), so probably not a crime or an affair or anything like that. The general vibe of the statement is that of "I should've known better", imo.
