Sho, an adult exam candidate, gets a surprise call from Ran, the childhood friend who once lived next door. She is also preparing for entrance exams and asks to stay at his apartment while attending winter classes. When they reunite, the formerly flat-chested girl he teased has grown into a gorgeous, big-titted woman. Her braless loungewear and shameless teasing destroy his restraint, leading to ten sweet and filthy days of nonstop sex and repeated creampies.