It's not just that, it's that both Koki and Ueda have been in love with Jin and Kazu for a long time. Since neither one has had the courage to confess it's tearing them up inside and one or other has always belonged to someone else. I am trying to write to where there is this self-destructive aspect to it so I am still kinda writing at the same time as I post what's already done. You know they spent 8 days in the TD? Well, I am expanding that and just changing the location.