A New School
Aya is first introduced with her friend Kanzaki Miki when they witness Onoda's despair after he finds out that Sohoku's anime club has been disbanded due to lack of membership. Onoda initially asks them both if they want to rekindle the anime club, mistaking them as interested, but they decline and say they are joining the tennis and bicycle racing club respectively. Aya is creeped out by Onoda's otaku demeanor, but Miki remains respectful. When Aya suggests that Onoda is probably going to Akihabara, Miki reminds him that the next bus there leaves soon. Her concern flusters Onoda, and he blurts out that he's going by bike before running off, thinking Miki's kindness is an exception to how sports club members usually are.
Later that day while Imaizumi Shunsuke is witnessing Onoda's climbing ability, elsewhere at the school, Miki, standing with Aya and holding a timer, reflects on her brother's words that some people are born with an innate talent for cycling while other's aren't. While Aya mentions how some people have played a sport since they were young, Miki says that experience doesn't matter in cycling because everyone has their own strengths. Miki becomes excited as Sohoku's cycling club arrives at the school, but finishes her thoughts, telling Aya that there are some people who appear normal but have yet to discover their true talent, foreshadowing Onoda's potential and contrast to Imaizumi.
The next day, Aya and Miki witness Onoda dropping several anime club recruitment flyers, which causes Onoda to run off embarrassed into his classroom as homeroom is about to start. However, Miki stops him by calling him by his family name - something Onoda never told her. Aya listens as Miki explains how she followed Onoda, doing research until she got his name from his homeroom teacher. Seeing how he panics when Miki introduces herself and says she has something to ask him, Aya guesses correctly that he forgot about her. Although he doesn't remember Miki at first, Onoda bows and apologizes for running off after scaring her the day previous, and thanks her for encouraging him. Aya scolds him for bowing to classmates, which she considers creepy.
Miki then asks Onoda if he really went to Akihabara by bike. Onoda freezes, his mind reaching a single conclusion after hearing someone ask about Akihabara: he tries to ask her if she's interested in anime, but Aya promptly silences him by hitting him in the face. Even though Miki thinks that wasn't necessary, Aya wipes her hands and says she just can't stand otaku. When it's clarified that Miki was asking about his bicycle, Onoda tells her that after he fell, his bike must have been damaged as the chain was broken by the time he reached home. Aya demands he say whether or not he went to Akiba by bike, but the bell rings, signalling classes will begin. Giving up, an annoyed Aya starts to leave, scolding Miki for being a "bicycle otaku" and getting so excited about bicycles, which Miki smiles and takes as a compliment, much to Aya's frustration.
When Aya says there's no way someone could go all the way to Akihabara and back by bicycle, Onoda clarifies that the chain on his bike broke after he'd come home from Akiba. The startled girls freeze and turn to him, but his teacher closes the class door, leaving them speechless in the hallway.
At lunch, Aya claims Onoda was lying, saying that he probably just wanted to get Miki's attention because she's cute. Miki disagrees, saying he doesn't seem the type to lie and it would be amazing if his claim is true. Aya facepalms, as realistically, it would take someone four hours to get to Akihabara and back by bike. However, unbeknownst to her, Onoda, eating lunch, has a new capsule toy from Akiba thanks to the money he saved by not taking the train.
When she learns that Imaizumi challenged Onoda to a race, Miki invites some of Imaizumi's fangirls to be spectators. In the anime, this includes Aya, who is a fan of Imaizumi.
In the anime, Aya visits the inn team Sohoku is staying at on the night before the third day of the first Inter High, revealing that she has relatives in Hakone. She's there to cheer for him at the end of the race.
Aya asked Miki to bring her along for the second Inter High after the tennis team lost at Inter-High Qualifiers, and Aya appears to express a bit of interest in the happenings there.