Dear Brother (1991)

An adaptation of the short-lived manga series "Dear Brother" (1974) by Riyoko Ikeda. The insecure and somewhat lonely girl Nanako Misonoo starts her freshman year as a student as a student of the Seiran Academy, a prestigious and exclusive girls' school. She is unexpectedly chosen for membership in the school's prestigious sorority, despite not meeting the usual standards for membership. This attracts envy and bullying by girls who feel left out. Meanwhile Nanako gets involved in the personal lives of three popular but troubled female students. She has a close but rather strange relationship with Mariko Shinobu, a girl who wants to be her best friend but does not like sharing Nanako's company with anyone else. Distraught by the conflicts, rivalries, and problems of everyday life, Nanako confides her thoughts to her surrogate brother Takehiko Henmi through a series of letters. Takehiko is a college student who was Nanako's favorite tutor in recent years, and she remains close to him. Nanako remains unaware for some time that Takehiko is her paternal half-brother, the result of her father's previous marriage.