Rakuen Danshi: Beast Harem (2006)

Youko is a normal high school girl attending a not so normal high school. You see Youko’s school used to be an all boys school, so after transferring to this school she is the only female in her class, and that surely can cause a few problems. She is being constantly teased by her classmates, especially by Mastsushima Soushi, who she hates the most. But not everything is bad, Youko is in love with Narumiya Kouei, the only one who helped her since she entered the school. But if the one Youko loves is Narumiya, why does she finds it so hard to stay away from Mastsushima, who she 'hates the most

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