Unhappy after his new baby sister displaces him, four-year-old Kun begins meeting people and pets from his family's history in their unique house in order to help him become the big brother he was meant to be.
The life of a young, Japanese schoolgirl is destroyed when her family is killed by a Ninja-Yakuza family. Her hand cut off, she replaces it with various machines-of-death, and seeks revenge.
As Sakura drowns in the murky darkness of the sins she has committed, Shirou's vow to protect her at all costs leads him into a raging battle to put an end to the Holy Grail War. Will Shirou's wish reach Sakura even as he challenges fate itself in a desperate battle against the rising tide?