Cencoroll (2009)

Yuki discovers one of her classmates, Tetsu Amamiya, taking care of a bizarre creature he calls Cenco, Yuki wants to learn all about the strange but lovable being. However, when another student, Shuu, attacks Cenco with a creature of his own, Yuki realizes that she might have gotten in over her head. As Tetsu and Shuu battle, Yuki fights to protect both herself and those she cares for. [Written by MAL Rewrite]