Oniisama e...: Season 1

Misonoo Nanako is a professor's daughter looking forward to her first day of school at the prestigious Seiran Academy, a girl's only school that caters to the rich, or in her case, those with high test scores. She soon finds that the school is polarized by three popular and talented individuals, known as the Magnificent Three, and known by their nicknames: "Kaoru no Kimi", a boyish, but talented sports player named after a character in The Tale of Genji, "Saint-Juste", a flamboyant pianist named for a French Revolutionary character, and "Miya-sama", the president of the Seiran Sorority, an elite group of the most beautiful and talented girls of the school. Though Nanako doesn't intend to make waves as a student at this school, when she is tabbed to be a member of the Sorority, the brutal politics that run beneath the surface of the school's sophisticated veneer soon threaten to pull Nanako's life into chaos, and her world becomes one where she is unsure of her friends, her enemies, and her very identity... and the only way she can vent her emotions is through her correspondence letters to a man she calls her "Dear Brother". This series is based on the manga created by Ikeda Ryoko, who also created The Rose of Versailles.