At the beginning of the academic year, Saotome Hodaka enrolls in Moteshiro Prefectural High School, a former all-girls school that had recently integrated, but discovers it has a male-to-female ratio of 1:359!

While most might consider this a paradise, the majority of the students are delinquents and Saotome immediately finds himself being extorted by some of the more aggressive girls. However, he is inadvertently saved by Hanako Kuzuryu, a beautiful Yankee who just wants to be left alone.

Is this the start of a new friendship? And how will Saotome's life unfold in a school full of troublesome women?