From KodanClub:
A reform school for juvenile delinquents established in 200X is actually a government-sponsored laboratory, which makes ultra-human warriors with genetic modification. Three new kids enter the school. Itsuki, who is actually a girl dressed as a boy so she can get into the school to look for her lost brother; Mei, a very quiet, mysterious boy; and Gentaro, an energetic boy who is easily elated by flattery. The three revolt against the school rules and cause the other students to riot. The school turns into a battlefield.