Meteor Methuselah (Immortal Rain in the U.S.) is a manga series I reviewed in this blog post. Tohou Shinigami (Shinigami of the East) happens to be a 1 volume long prequel to Meteor Methuselah. Remember Machika, the quirky girl that is trying to capture Rain (aka Methuselah) in the beginning of Meteor Methuselah? Well, this prequel follows the life of her grandfather, Zol, who was known as the shinigami (grim reaper in Japanese mythology) bounty hunter. The only bounty Zol was unable to capture was the immortal Methuselah and this volume seeks to explain why that is.
What would normally have been a short story of 1 or 2 chapters, led to the creation of an entire volume because by this time, we know that when Rain is involved, things don't go as planned. We start out on a scene of Zol who executes a sneak attack on a ring of criminals and then collects the bounty. Zol takes the bodies back with him and the villagers comment that the reason he does this is because he simply enjoys killing. However, Zol takes the bodies and then buries them, giving each grave its own cross that extends toward the horizon. It's on his way to bury this new batch of bodies, that he stumbles upon Rain.

