They're called Monsters: people with the power to assume animal forms, kept segregated from the rest of society. When he was young, Riku befriended a Monster boy named Tsukasa, only to be separated from him. Now, at an academy for Monsters, Riku has finally found his childhood friend. But can he overcome the distrust of his more-than-human classmates and reconnect with Tsukasa? And will their adult relationship be as close as their childhood friendship... or even closer?