Aya Kurihara is a French-Japanese transfer student who had a run-in with Yoshihiko when he looked for a ball that sauntered into the library's window.
When he crawled to look for it, he knocked the stool where she was standing. Luckily he caught her falling... and after getting a feel of her "lumpy" side, he daydreamed about her. At the start of the second episode, she was the one secretly watching Yoshihiko from a library window.