I don't remember much but it was about a boy that killed a monster but was cursed when he killed the beast and the arm he made the final blow with becomes part of the beast. This is during samurai time and gun powder is just being introduced by bamboo hand cannons. The boy ends up going to a forest with talking beast to find some tree that can heal him. And meets a girl raised by wolves and falls in love with her.
Anyone know this? If so pm me please because my iPhone does not want to load the forums.