Product description ※Please note that product information is not in full comprehensive meaning because of the machine translation.
Bon Private Academy.
There were sons and daughters of nine famous families called several families enrolled in this academy, and they were respected in the academy.
They had secrets, and there was a battle that only they could do at this academy.
It was called the "battle of numbers", and the rank among several families and the head of the "Bon" who controlled several families were regularly decided by this battle from long ago.
However, it has been said that this battle can never be fought again because of the lack of one number.
However, by the "number that should not exist" that suddenly appeared before them, the condition of the battle of numbers is satisfied …
-- when the number of ten is gathered, the inscription shows and guides to the land of battle --
The name is Hiroka 0 saki.
She tells the beginning and the end.