Who is Tamaru from 1Q84 and what is their importance?

Tamaru is the Dowager's bodyguard. Tamaru is an agnostic, brought up in a cold and unsympathetic Catholic orphanage that soured his faith. Over the course of the novel, he becomes friends with Aomame, and even comes to consider her family. Tamaru murders Ushikawa and serves as an intermediary between Tengo and Aomame at the end of the novel. He also becomes Aomame's protector.