Black Star and Tsubaki take a specific mission, to take on the dark weapon Masamune. But before they go on this mission Lord Death speaks to Tsubaki alone to make sure this is what she wants and to let her know to be extremely careful since this mission may be much to hard for the both of them. But Tsubaki has a clear mind about what she wants, and the reason she joined the academy in the first place was for this fight alone. She is reminded that her name Tsuaki means the silent flower without fragrance.
Masamune is on the verge of becoming a Keishin, his evil knows no bounds and he is traveling from village to village to possess people for his own bidding’s.
Black Star and Tsubaki go to the town that he was last seen but the village is more afraid of Black Star then they are of Masamune because of Black Star’s tattoo which associates him to the Star Clan, a furious ninja clan known to pillage and kill innocent people. The Weapon Meister academy vanquished the Star clan years ago when Black Star was a child, but since he was so young the academy took him in which is how Black Star came to be at the Academy in the first place.
Masamune can possess people easily based on their wants which makes him that much harder to defeat because they can not kill his possessed people. But Tsubaki is able to enter Masumune’s sword directly and fight him one on one to finish the battle she started. Once inside the weapon the fight is more personal than anyone else knows.