Kana Arima

Introduced in the prologue "Childhood," she is a former child actress who has been in show business since she was a baby, making her age equal to her years of experience. She is one year older than Aqua and Ruby, and the same age as Akane Kurokawa. Known for wearing a beret since her child acting days, which has become her trademark. She stands at 150 cm tall and is the only main character who uses her real name, Kana Arima, in her entertainment career, as evidenced by her autograph on a contract with Ichigo Productions. Despite her youthful and cute appearance, of which she is aware, she lacks confidence in her potential as an idol. She is sarcastic and sharp-tongued, often using strong language when emotional. She adapts well to others' acting on stage.

As a child actress, she was known as a "genius child actress who could cry in 10 seconds" and was confident in her acting skills. However, after seeing a performance by Aqua that captured the director's intentions, she felt defeated and has been conscious of Aqua ever since. Ruby once mistakenly called her a "genius child actress at tasting baking soda" and directly told her she didn't like her because she seemed fake, which did not leave a good impression. Although she calls Ruby "just a pretty face," she recognizes Ruby's potential and future in the entertainment industry, reminiscent of Ai.

In Chapter 2, as a senior at Youto High School, she reunites with Aqua and others. Her work has decreased as she is past her prime, but she has learned to cooperate and contribute to the quality of the productions without insisting on her own way. Initially freelance, she was not affiliated with any agency, which led Ruby and Aqua to recruit her into their idol group (later known as New B Komachi). Initially reluctant, she was persuaded by Aqua's passionate appeal and joined Ichigo Productions as an idol.

She has released several CDs during her child acting days, but except for the number one hit on Oricon, "Pepper Exercise," they were not successful, leading her to claim she lacks singing talent (though she has improved significantly by Chapter 4). However, since the other two were much worse, she reluctantly became the center of New B Komachi. Her member color is white, and she refers to the "Pepper Exercise" as a symbol of her "straying period" and a "dark history."

She has known Akane Kurokawa since their child acting days and views her as a rival, as Akane has blossomed into a popular stage actress while her own popularity has declined. She kept her distance from Aqua until she realized that Aqua and Akane's relationship was purely "business."

She frequently reads books titled "Easy to Understand [Subject]," such as "Easy to Understand Money Trading," "Easy to Understand Frilled Lizards," and "Easy to Understand Internet Sea Slugs."

The character is modeled after the style of Akasaka Aka, the original creator. Known affectionately by the author and readers as "Baking Soda-chan," this nickname has also caught on among fans of "B Komachi" in the story, as seen in her interactions with Ruby.

She harbors romantic feelings for Aqua, which profoundly affects her mental state and extends to her entertainment activities, making her highly susceptible to Aqua's influence. Despite her twisted and sharp-tongued nature, in the activities of New B Komachi, she strongly wishes to spare Ruby and MEM-cho from experiencing the setbacks she has faced.