Overview:

Aomine High School is a seemingly ordinary high school, quietly located in the hustle and bustle of the city. The students here live ordinary lives, but behind the campus lies the shadow of the Yakuza. The Shadow Gang, which has been expanding in recent years, is not only taking over the school, but also threatening the safety of the students.

The protagonist, Erin, is a high school student at Aomine High School who is strong-willed fighting girl. Her family suffered a tragedy when they fought against the Shadow Gang, but she is determined to change everything. She begins special training in secret with the goal of exposing the crimes of the Shadow Gang.