By Seturi Tsuzuki.

Hiro is popular with the girls at Sunao's high school--but he's been in love with his cousin, Saya, since childhood. Angry that Hiro would choose her over them, the jealous girls at school decide to expose a dark secret from Saya's past... Later, it's vacation time for Sunao, as she and Kureha arrive at a mountain lodge, where they meet star-crossed lovers who end up going to extremes to prove their affection for each other.

For age 16+, English manga graphic novel.