A tale of immoral youth drowning in uncontrollable urges during summer school. Kawagoe Niko, also known as Mita Marin, are two best friends in uniform. Behind their innocent and pure smiles, they desire each other's bodies in the middle of the day, going beyond friendship and becoming entangled in lust. Covered in sweat and semen, after school they are dominated by unstoppable pleasure. The intense and immoral threesome that unfolds at the pool, in the classroom, and at home will become an unforgettable summer memory. The moment when innocent smiles are distorted by pleasure. A portrait of immoral youth, whose minds and bodies are disturbed by this contrast.