Kono Yo no Owari e no Tabi

Kono Yo no Owari e no Tabi (この世の終りへの旅, lit. "Journey to the End of the World") is a manga series by Nishioka Kyoudai. It was serialized in AX.

Plot
A man sets out on a journey to go away from his repetitive and boring life. He finds unbelievable things, terrible things.