Nina is a tall and slender girl, being much taller than her twin sister. Like Sara, she has very long silver hair, reaching past her waist, and also purple eyes. She is usually seen wearing her school uniform, a serafuku composed of a dark grey blouse with a black collar and a black skirt, and a dark red ribbon.
According to Sara, she is smart and has good grades, but is also stubborn. Unlike Sara, she's skeptical, and doesn't believe in fate and superstitions, but believes in making your own chance. She is more mature than Sara, but is also very careless and gets worried easily.
Nina acts as the older sister, despite being the younger twin, and refers to Sara as "Onee-san". She's overprotective of Sara and worries about her well-being. She wants Sara to be with her "predestined person" (Mei) and tries to get them together, also trying to keep Yuzu from getting in their love's way.
She was very thankful for returning her sister to her and they became friends but was angry at Yuzu for trying to get in the way of Sara's and Mei's date. She knew of Yuzu's feeling towards Mei's but still chose her sisters happines over her friendship with Yuzu. it gets resolved in the end and eventually they have a good relationship.
She seems to like Mei only because Sara believed she was her predestined person and was hoping to bring them together however it fails at the end. But she see's her now as a good friend to sister.
- (To Sara) "If a chance appears, you have to take it, right?" 
- (To Yuzu, about Sara) "Onee-chan... She just helps others, and always puts her happiness in second plane." 
- Nina is a feminine Russian name derived from original Georgian form Nino. Being a Christian name, it dates back to Saint Nino. The name Nina may originate from the old Slavic word Ninati, meaning "dreamer" or "dream". Other origins for the name Nina include - Native American, Spanish, English Croatian, and Indian. In Europe it is a short form of names such as Marina and Katharina. Other possible meanings include "mother" (Swahili), "flower" (Old Greek), and "fire" (Quechua).
- "Tachibana" (橘?) is a type of wild, inedible citrus fruit.
- Like Yuzu Nina also reads Momoiro Shimai.