LULU-401 - A story about two friends becoming sexually involved. The male experiences arousal due to the female's unintentional exposure, and they engage in repeated sexual acts, providing each other with deep satisfaction.

A story about two otaku friends becoming consumed by sexual desire and falling into a sexual relationship. The male otaku can no longer resist the female otaku's unintentional exposure and initiates sexual activity. The male experiences a female's genitalia for the first time and feels increasingly intense sexual desire. Both release their pent-up sexual desires and continue to have intercourse repeatedly until their sperm is depleted.