Hikaru is a young college student still carrying the innocence of youth. Inspired by her friends' romantic stories, she begins to take an interest in relationships and turns to a dating app to find a partner. Soon, she becomes involved with a man older than her father, undergoing profound physical and emotional changes. Still inexperienced, she desperately tries to meet the demands of an adult relationship. Through erotic experiences, she gradually matures into womanhood. Shy and reserved at first, she slowly learns to open up and reveal her true self. This is a shocking story depicting the transition from pure adolescence to adulthood.