Fumetsu no Anata e

From Kodansha:
An epic story spanning time and space. A lonely boy wandering the Arctic regions of North America meets a wolf, and the two become fast friends, depending on each other to survive the harsh environment. But the boy has a history, and the wolf is more than meets the eye as well. To Your Eternity is a totally unique and moving manga about death, life, reincarnation, and the nature of love.

Official English