Miya has black hair and black eyes. She has slight resemblance to her brother. In school, she wears their standard school uniform.
She is a playful girl, and tends to call her brother "Nii-Nii" which sometimes annoys Junichi secretly. She tends to be jealous when her brother is with another girl, with the exceptions of Sae, Ai and Rihoko, who are her close friends. She was always seen walking home with Sae and Ai. She also has a habit of teasing Sae when it comes to Sae's breast. Her favorite food are meat buns.
She is shown to care a lot about her brother as seen in episode 26 where it is implied that she is concerned as to why her brother does not have a girlfriend
She makes a debut in the anime when she goes to wake up her older brother on the first episode
- The name Miya means "beautiful" (美) (mi) and "to be, also" (也) (ya).
- Miya's surname Tachibana means "orange, tangerine" (橘).
- Miya's arc is the OVA of the series.
- Miya is the only support characters to have her arc in both anime seasons.
- In the OVA, Miya bites Junichi Tachibana's neck, telling her it was a "playful bite".
- It might be referenced to the series' title (Note: "Amagami" means "gentle/playful bite").
- Out from all the 6 main heroines, Miya only dislike Haruka Morishima at first.