Aunt Yuriko takes in her nephew Shoichi, who has moved to the city for college. Having doted on him since childhood, she finds herself overwhelmed with excitement and desire as she watches him mature into a handsome young man. Her seductive behavior deeply affects Shoichi, who has little experience with women, stirring intense emotions within him. Though his arousal reaches its peak, he continues to resist crossing the final line. Frustrated by his persistent resistance, Yuriko invites Shoichi's senior, Muneyuki, setting the stage for a new and provocative development.