I think it is the first one. Even if it is a little strange when you think about it since she collects all kind of Boko haha.
I agree with you about that. I think Arisu already has that boku what Megumi is holding from the comic, either that she bought it or came from her mother.
Remember from the movie what her mother promises her even she lose.
This might also indicate a seiyuu connection since both Boko and Megumi share the same seiyuu, Ayumi Fujimura, who is currently on indefinite hiatus in voice acting.
