|Height||160 cm (5'2")|
|Birthday||October 16 (Libra)|
|Relationship(s)||Mona Narumi (Younger Sister)|
Midori Hamanaka (Boyfriend)
|Occupation||High School Student, Model/TV personality|
|Song||Kinyoubi no Ohayou|
|Anime||Zutto Mae Kara Suki Deshita. -Kokuhaku Jikkou Iinkai-|
Sena is a slender teenager with a fair face and skin. She usually wears her long hair in pigtails when she's at school or not on the job.
Hayasaka had known Sena ever since their middle school years, and are still close enough with each other to consider each other friends.
Sena's experience with Hamanaka isn't a very conventional one. They had only seen each other on the subway on the commute to school every Friday, but never worked up the nerve to talk to one another. Sena often spent time trying to practice greeting him for real, and eventually lent him her umbrella one day when it started to rain.
Sena is absolutely smitten with Hamanaka, calling him her "prince" despite his goofy personality. Her feelings for him become more apparent as they start hanging out together on Sundays, which eventually culminates in them officially dating.
Sena and Arisa never met before high school, and the relationship between them is purely fan and celebrity. Arisa is awestruck by her presence in Sakuragaoka, asking her various questions about her shoots and thanking her for being the inspiration for Arisa herself to change.
Has worked with both Yujiro and Aizo on occasion. They starred together in the "Romeo" music video, but their relationship is purely professional. Individual opinions on either boy are subject to change.
As Mona's older sister, she's incredibly supportive of her progress in show business and makes time and effort to come to her live performances when she can, often telling everyone she can about it.
- Sena takes her blonde hair from her mother, but her blue eyes from her father, as seen in the PV for the CHiCO with HoneyWorks song "Mister Darling".