Freak Island In Love summary:

(Edited from Amazon.co.jp)Love is absolutely forbidden! Kaworu, the "public disciplinary commissioner of justice," uses a chainsaw to purge all the men of their sins in order to protect the purity of the girls! Standing in Kaworu's way is the "boy with high femininity," Takahisa, and Kaworu's sister, Mari, the "demon public disciplinary commissioner." In this parallel world of "Freak Island" set in Santa Maria Academy, a storm of blood and love is about to... erupt!!?