I'd call the 1st seme yandere.
Looked yandere at first but seme is too sane to be really yandere imo, but still really cute. And who knows, maybe he'd snap and go crazy if mc cheated.
The story in chapter 3 and 4 definitely has a yandere. Possibly some of the other short stories too.
Stalker with some protective yandere moments. Not really crazy about it. (probably cause his lover just rolls with it...)
Chapter 5. Yandere feels, but it's so short you can't really tell.
I love this so much. And I get definite Yandere feels for the main LI. He's really obsessed. Though not the "If I can't have you noone can!" type of yandere. Though I mean. The MC doesn't really show interest in anyone else so...
Manipulative sadistic yandere~ <3
Free! dj - Goodbye Friend