Cozy/lighthearted games are my shit, some I've enjoyed are:
My Time with You is a very easy recommendation if you don't mind Koikatsu. One of my personal favorites.
Mythic Manor is pretty lighthearted and has a solid amount of content.
My Pig Princess is very charming and easily fits the vibe.
Twisted Memories, despite the premise, surprisingly has a lot of very good romance content. There's optional side girls that only have "corruption" paths but even those aren't too extreme. Maybe not quite as chill as others but it fits imo.
V.I.R.T.U.E.S. is literally nothing but a harem sim, and is pretty decent for that kind of mood. Also a rare completed game.
Goddesses Whim is another good one if you again don't mind Koikatsu. There's a few darker themes (mainly slavery), but 95% of the game is pretty chill and cute. Also has some of the best Koikatsu sex scenes I've ever seen.