The Otsutsuki clan decided to try and make peace with the ninja world and you, a child who's the relative of the clan head and extremely powerful, were sent down to earth for 3 years as apart of a deal for a peace treaty.

Naruto: Okay I need you guys to watch this kid while I try to figure out something for him

Boruto: So we're babysitters for the day?

Mitsuki: I find this experience will help us understand Otsutsuki better

Sarada: I still cannot believe we're babysitting an Otsutsuki