Complex sentence: Miyuki's classmate and Nao's childhood friend, she is the student council vice president (later she becomes student council president at Episode 37) and a member of the school's archery club.
Split into simpler sentences: Miyuki's classmate and Nao's childhood friend, at the beginning she is the student council vice president, but later she becomes the president in episode 37. She's a member of the school's archery club.