Mutsuhiro Watanabe a.k.a. the Bird Timeline & Summary

Watanabe obsesses over Louie the moment he sees him at the Omori POW camp.
He beats Louie with a belt buckle and is generally abusive toward everyone, except when he has his weird mood swings and suddenly turns nice.
When a POW manages to report the Bird's actions to a Japanese dignitary, he is ordered to leave Omori.
However, he gets transferred to Naoetsu, and Louie soon follows.
The Bird turns his torture up to eleven, beating Louie, ordering him to clean a pigsty with his hands, and forcing him to do unsafe manual labor jobs.
The men try to kill the Bird by contaminating his food with bacteria, but he survives.
When the war ends, the Bird goes into hiding.
He even manages to fake his own death (although maybe not intentionally) and stays hidden until the arrest order for war criminals is lifted.
A free man, he manages to make a nice life for himself.
Years later, he's discovered by a reporter for 60 Minutes and he gives an interview.
Louie tries to find the Bird so that he can talk to him in person and forgive him, but the Bird refuses.
He dies in 2003.