|Relatives||Yu Saikai (father; deceased)|
|Anime Debut||Season 1 Episode 1: Boy Meets Girl|
|Seiyuu||Hisako Kanemoto (金元 寿子)/Asami Seto (瀬戸 麻沙美) (Japanese)|
Tsubasa Sumisora (澄空 つばさ Sumisora Tsubasa) is the main protagonist in B-Project: Kodou*Ambitious. She is the new A&R hire at Gandara Music, overseeing the idol unit B-Project. She is currently being 'trained' by the company but follows the groups and assists as a usual A&R.
Tsubasa has reddish brown hair tied back into a ponytail with a red ribbon and yellow clips on the right side and red eyes.
In the first season of the anime, her main outfit is a blue jacket over a white shirt paired with a red skirt, brown laced up boots with blue socks, a black and gold watch on her left wrist and a necklace. In Episode 8, she wears a white shirt with checks paired with pale blue shorts and sandals. Her main outfit later changes to a black jacket (similar to her blue jacket) over a white blouse with a green vest, paired with a red skirt, tall brown boots and a gold necklace. She wears a large pink coat to accompany her second outfit.
In the second season of the anime, her main outfit consists of a pink jacket over a white turtleneck paired with a turquoise skort with a white belt, tall brown boots and a gold necklace. She wears a large vermilion coat with a hood to accompany this outfit. Her main outfit later changes to a pale turquoise shirt with pink decorations and transparent short sleeves, paired with white trousers, and pink flats. In Episode 8, she wears a black suit. She switches back to her first outfit from the beginning of the second season in Episode 10.
Tsubasa is shy at first upon meeting the B-Project idols, but becomes a more outgoing person as the series progresses. She has an honest personality, and does her best to remain positive in every situation. Tsubasa is also independent when she tries to do things by herself, but she does ask questions when needed to. However, she can be modest and doubtful of her own abilities in certain cases. She is also selfless and brave when she puts other's before herself.
- Before she was suddenly hired to work at Gandara Music, Tsubasa's previous job was working as an assistant in a CD shop.
- She has a very keen hearing ability to any type of distinction in music, which has been demonstrated in the first and third episodes of the anime's first season. When she was asked about how she came to be able to recognize differences in music, she mentions her father but seems a bit saddened by him.
- In the final episode of the first season, Yashamaru claimed that Tsubasa's father "killed" his family ten years ago. However, Tsubasa didn't know what he was talking about.
- The voice actress of Tsubasa, Hisako Kanemoto announced in May 2018 that she would be going on hiatus to study abroad until March 2019. She was replaced by Asami Seto, who voiced Tsubasa for the anime's second season.
- In the seventh episode of the second season, Yashamaru claimed that her father betrayed his sister by giving his song she was supposed to sing to another artist instead.
- In the eighth episode of the second season, it is revealed that her father was Yu Saikai, a famous composer whose music "set the world on fire". He had already passed away twelve years ago prior to the start of the series. Tsubasa only knew he worked as a musician, but had no idea he was very famous. She also doesn't have a lot of memories of him due to the fact he was very busy and was hardly at home, but she remembered him as a very kind man.
- Her given name "Tsubasa" (つばさ) means "wings", while her surname "Sumisora" (澄空) means "clear sky". Momotaro once referred her as "B-Pro's wings".