Is it me or is it really naive for ritsu to think he can totally be being a substitute parent for his brother and a student at the same time and support both of them and work 125 part time jobs ? does his biological mother will even allow him to take the kid with him ? because you know, you can't just ''' kidnap'' a kid like this, if the mother wanted to call the cops over this, she would have all the right to do so.
i mean, being happy to have someone taking care of the kid you don't care about is a thing, but giving up your parental authority to this person is another, if she really wanted to abandon ruka, she would already have done it