Two female college students, Kokomi and Meru, come on their graduation trip to a secret hot spring inn deep in the mountains. Near the inn is said to be a power spot for love known as the "Waterfall of Happiness." However, this trip is actually a revenge trip meticulously planned by her jealous best friend, Meru. Kokomi has no idea that even the owner of the inn is in cahoots with Meru. She is suddenly drugged with an aphrodisiac, and Meru films all the perverted training she goes through, including bondage sex, humiliation restraints, and gangbangs. Then she ends up getting fucked by multiple cocks in front of her best friend...