The younger sister of Buzou High School Quiz Club Captain Gakuto Sasajima. Although people notice they don't look alike enough to be siblings. She was first introduced as the mystery girl riding on Gakuto's bicycle on the way to school. Then, she met Shiki in his usual spot in the library. Weakened by hunger, Shiki shared his food with her. It is implied that she is into electronics, as she had unknowingly left an Electronics book with Shiki on the first time they met. Shiki and Daisuke find it "moe" due to the fact that "cute girls buying electronics at the Akihabara district" are rather rare. As such, it is implied that she is learning how to make buzzers at a cheaper cost since they're usually expensive.

Bunzou High School is welcoming its new first-year students. One of them, Koshiyama Shiki, is chosen to participate against his will in an impromptu fast-buzzing quiz meet by the president of the Quiz Bowl Circle. As a quiet boy who loves reading and doesn't want to stand out, Shiki is overwhelmed, but his classmate, Fukami Mari, is able to hit the buzzer and answer questions before the full question is given. As he watches her, Shiki realizes that there's a point in each question where the answer becomes certain.
<br><br>
(Source: Crunchyroll)

Satsumi Matsuda is the twin sister of [Risae Matsuda](https://anilist.co/staff/119960), although Satsumi was born after midnight so they do not share birthdays. Both were the 4th and 5th Anisong Grand Prix Finalists with [Marina Kawano](https://anilist.co/staff/107072) (4th) and [Konomi Suzuki](https://anilist.co/staff/110607) (5th). She is affiliated with Arts Vision.

[Profile](https://www.artsvision.co.jp/talent/534/) | [Blog](https://ameblo.jp/7-16r17s/) | [Twitter](https://twitter.com/DApanda323)

As soon as he entered high school, the first year student Koshiyama Shiki was invited to the mysterious Quiz Study Group led by his senpai. What will Shiki run into when being dragged along by his classmate Mari into the dazzling world of competitive quizzes?!<br>
<br>
(Source: ComicWalker)

Jinko Sasajima