Yū Ōsawa takes an interest in the silent transfer student, Koizumi, and ends up joining her in line for a ramen shop. Picking the same pork ramen with garlic and extra vegetables as Koizumi picked, Yū bears witness to Koizumi's love of ramen, getting to see a side of her that she does not usually show. Later, Yū goes to the school cafeteria to try its Māyu ramen, learning about the various kinds of ramen from Koizumi. On another day, Yū follows Koizumi to another restaurant where she indulges in a ramen made from a rich broth.

Worried over whether Koizumi has a boyfriend, Yū follows her to a Western restaurant, where she seems to meet up with a bunch of guys. To her relief, Yū discovers that Koizumi was simply waiting for an open space in a ramen stand behind the restaurant. Later, Yū goes to a ramen restaurant with Misa, each ordering red Akamaru ramen and white Karaka ramen respectively, while Koizumi goes to it moments after they leave. During the weekend, Jun comes across Koizumi at a convenience store and tries out her recommendation of instant ramen.

Yū tries to recall a tasty ramen she ate in Osaka when she was a kid, which turns out to be a dish literally called Tasty Ramen. After Yū and Koizumi go to a Tokyo branch at Kabukichō to try the dish, Koizumi goes on a ramen pilgrimage to Osaka where she encounters a woman named Ayane. Serving as Koizumi's bodyguard against guys trying to pick her up, Ayane accompanies Koizumi during her remaining ramen stops. Hearing about how Ayane is due to leave Osaka after quitting her job, Koizumi takes her to a ramen restraurant that she remembers from her childhood, but is later slightly disconcerted upon discovering that Ayane is actually Yū's cousin.

While heading home from Osaka, Yū ends up stranded in Nagoya after seemingly spotting Koizumi from afar and hopping off the train. With only 500 yen on hand, Yū goes to a fast food ramen shop, where she thankfully runs into Koizumi. Later in Autumn, Koizumi catches a cold and ends up taking several days off school, her continued absence taking its toll on Yū. After Koizumi eventually recovers, Yū decides to leave her alone to let her enjoy her first ramen in weeks.