It’s similar to Toshishita Kareshi no Renai Kanriheki, where there’s a graduate researcher and his kouhai keeper; I think the kouhai started out as just the uke’s lab assistant, but became his keeper because the uke is really bad at taking care of himself. The uke isn’t a yandere, but the seme is still possessive. The uke is also bad at interacting with other people because he’s so timid (from what I remember) There’s also two other students in the lab (it’s a nice sized lab).
I remember the seme got mad at the uke for a specific reason and went to work at a different workstation, but came back over to the their shared workstation when the uke broke a glass, started bleeding and cried.
(I also remember a scene from later, but it’s a spoiler so I didn’t include it yet)
Personally, I dont mind harem in manga, as long as the series is entertaining. This series is entertaining to me. It's the kind of silly funny that can make you smile/laugh when real life is just so sh*tty you need an escape.