Aika, a college student who has returned home during summer vacation, is delighted to see Haruna, Yankee, and Nana. All four grow up in families where premarital sex is prohibited. Four childhood friends with no sexual experience spend the summer trying to lose their virginity. Haruhi Oguri, the female director who was the first to challenge the pink film, vividly reflects the sexuality and life of women with different complexes and habits, and this work of her was highly praised.