^It's there. There's a lot of Tohru being thirsty and Lucoa being... Lucoa.... but that's mostly used as joke material. There's lots of gentle, family-ish kind of stuff, and a lot of the character development comes from becoming closer and getting to know each-other.
That's how I see it at least.
@BugDevil Isn't Wally technically the rival R/E/S? I may be remembering that gen wrong but doesn't it usually go the other PC is your "partner" and the 3rd tag along is technically the rival?