One day in the summer, the family went to the beach. Tetsuro, the son, accidentally peeks at his mother Mitsuko peeing in the shade... He never forgot the excitement he felt at that time, and ever since then, he has been dying to see his mother pee. After thinking it through, Tetsuro finds a diuretic on the internet, gives it to Mitsuko when she gets home, and makes her relieve herself in the garden.