The antics are mostly because of Tsukasa’s younger sister but she is played out rather swiftly.
Im afraid on their own, this couple just isn’t interesting. Nasa Yuzaki wants to make a name for himself but the show never explores this desire. And to be honest I barely know anything about Tsukasa other than some vague tie-in to the moon. Maybe they’re trying to imply she IS Kaguya or has ties to Kaguya but for now she just sorta exists.
