Miho Fujikawa is the daughter of Ayano Fujikawa and the younger cousin of Yamato Akitsuki, being two years his junior. She is introduced as a young girl who lives with her mother and shares a close bond with her cousin. Her most defining trait is her deep attachment and protectiveness toward Yamato, which can manifest as jealousy toward anyone she perceives as a romantic rival, particularly Suzuka Asahina. She frequently brings up a childhood promise Yamato made to marry her, though she tends to mention this either as a way to cheer him up or in a joking manner, making it unclear how seriously she holds onto that pledge.

As the story progresses, Miho matures from a younger cousin into a high school student. Following a time skip, she moves into Suzuka's old room at the apartment complex and takes on the role of the track manager, showing a more responsible and focused side of her character. When Suzuka eventually returns to the apartments, Miho gives up the room and moves back in with her mother. In the sequel series Fuuka, she appears again as a supporting character, now serving as the landlord of Heights Asahi-yu, the apartment building where Fuuka resides, and continues to live with her mother Ayano and their pet cat Goro. Her primary relationships are defined by her family ties: her protective affection for Yamato, her rivalry with Suzuka, and her bond with her mother. Miho's role in the story is that of a supportive family member who evolves from a possessive cousin into a capable young woman managing the track team and later the apartment building, reflecting a steady but modest personal development over the course of the series.