" I took a picture of you drooling at your desk, Youko ! "
Arima (有馬) was Youko Tsubaki's boyfriend in high school who is featured in Anime Episode 13 and Manga Chapter 19.
Youko Tsubaki recalls that Arima was her boyfriend in high school. He even took a picture of her at her desk, drooling. When Youko was shown that picture by Arima, she wanted it discarded, but Arima refused, stating that she was so, so cute, with her hair in twin tails, and drooling. During high school. Youko and Arima went on a date at a karaoke parlor. Youko wore a particularly sexy and provocative outfit, and ended up popping a surprise kiss on Arima, the first time she had ever done that with anyone. After high school ended, he attended a university in the Kansai region. He and Youko stayed in touch for half a year, but slowly grew apart. Because of not staying with Youko, that implies that Youko may have lost interest in him because she was never able to Drool Bond with him, possibility because, like Kouhei Ueno and Ogata, he does not have drool capabilities.
Years later (as shown in Chapter 85 of the manga), when they are both young adults, Youko has a chance meeting with Arima. They spend some time together, but the encounter leaves Youko somewhat emotionally upset, possibly with regret that she had a passionate lover's relationship with him, but the shipping never was consummated, and gradually faded over time. Youko is so moved by her emotions, that she invites Mikoto Urabe to share a bath together with her in a public bathhouse, and tells Urabe everything that is on her mind about Arima. In return, during the very intimate interlude between the two young women, Urabe reveals that she is an intimate girlfriend of Youko's younger brother, namely Akira Tsubaki.
- In the Japanese language, the surname Arima is masculine, and means "exist" (有) (ari) and "reality" (真) (ma).