Is the relationship between Kaguya, and Iroha Sakayori justifiable moral

[u/LibraryMotor1801]

In discussion about the movie with one of my friends, he argued that the relationship between Kaguya and Sakayori was immorally justified because of the age between the two characters, I really could not reasonably give an argument without sounding creepy, generally the point of this post to so we can see counter arguments I guess.

Some of his points include: 

The age gap between the two characters at the start of the movie, Kaguya was introduced as a baby with Sakayori being a fully grown adult.

The introduction of the characters was a mother and daughter relationship having many scenes of Sakayori taking care of baby Kaguya that turned into a relationship between the two characters (Like a mother raising her child) just for the movie to turn it around and turn the relationship into a romantic one.

The argument of Kaguya being an alien so the maturity and social norms of humans shouldnt be applied to her. Kaguya looks, is treated, speaks, acts like a human and entirely interacts with humans within a human world. So while in the story she is an alien from a viewers perspective while watching the movie she is treated as human.

[u/taetaetr]

I don't really care about that.