A hard working sprinter of the track team who is on an athletic scholarship. Even though he is a talented sprinter, he is not as fast as Yamato in the 100 meters. He dislikes Yamato because he outperforms him in track and Honoka, the girl he likes, at the time only had eyes for Yamato. Like Yamato, he was scouted by the universities in his senior year at high school. When Yamato and Suzuka told the high school track club that they dropped out of Seijo University, he was the only member that was upset about their decision; there is also a running joke that in every picture he is in, he is cut off or just barely seen. Arima and Kenji represent Japan in the 100m and 200m.