“I heard you have a request for me.”

There is a debt that can never be repaid even if you sacrifice your whole life. People call it "acknowledgment."
Tsubame, the abandoned hound, could never forget the acknowledgment of the stranger who taught her what a "normal life" was without even asking about her past.

Tsubame vowed to repay that kindness for the rest of her life. But that promise is now impossible to keep...
Those who had been her former masters had returned, stolen her second life, and burned everything to the ground.

For the first time in her life, Tsubame felt the killing intent of her own will. She wanted revenge.
Even if it meant spending the rest of her life in hell.