I'm not actually asking this for me, but a while ago I saw a forum post asking for dramas like this but for the life of me I can't find it, so instead I'm posting this for anyone who's interested in dramas like this to find . . .

While looking at the tags for "It's Okay, That's Love" I discovered there's actually a tag for cohabitation . . .

It's specified as, "The depiction of two characters, who are not married but have a romantic relationship, living together."

Anyway, here are two more dramas that fit for anyone who's interested:

Goblin: The Lonely and Great God

Pinocchio