Kanojo ni Naru HiСтань девушкой сегодня!; 变成那个她; 彼女になる日; 變成女友的那一天; 그녀가 된 날; Becoming a Girl Day; The Day He Becomes a Woman

Miyoshi is always competing and losing against his childhood friend, Mamiya, who is good at everything. One day, Mamiya collapses from illness and is hospitalized forseveral weeks. When he returns to school, it turns out he is genetically female, and has decided to try living his life as a girl now much to Miyoshi's horror.