With her parents away on a trip, Sakura—his now-grown, busty childhood friend—comes to stay at his house. An emergency also calls his parents away, leaving the two adults alone for the night. Bathing and sleeping beside each other once felt natural when they were children, but now every glance is charged with tension. During a sleepless night, Sakura makes the first move and they begin touching each other. Once they awaken to sex, even their parents' presence can no longer stop them.