Why did Hamura's descendants continue using the Otsutsuki name, but Hagoromo's descendants became the Uchiha and Senju? I'm thinking Indra denounced his Otsutsuki heritage after not being chosen by Hagoromo to be his successor, so he didn't give his child the last name Otsutsuki, but why would Ashura's descendants not have the Otsutsuki last name?