Mayumi has short brown colored hair, a small bust and a slim body figure. Her bangs curve inwards and cover part of her cheeks. Her eyes are light brown in color.
She has been seen mostly in a sailor fuku; dark blue when she was first introduced and white during the Karaage wars arc. Her casual wear mostly consists of simple blouses.
Mayumi is a shy and meek girl who usually lacks the self-confidence to stand up for herself or believe in herself. She was very easily intimidated by Kinu Nakamozu and felt overwhelmed by Ikumi's physical beauty. From her elementary school years, Mayumi developed a crush on her fellow classmate, Sōma Yukihira, who she thought was cool. Mayumi generally wants to do whatever she can to assist Sōma whenever he is around, but needs a friendly push from her friend Aki Koganei in order to initiate. At the end of every duel between Sōma and his father, Mayumi always tried to cheer up Sōma whenever he lost, but unfortunately became a victim of a multitude of Sōma's failed dishes as a result. Sōma puts a lot of trust in Mayumi, noting that Mayumi likes to take care of the little things like watering the school's flowers and tasks her with making the Sumire Karaage Roll in his absence.
Little is known about Mayumi's past. However, she was Sōma Yukihira's classmate since kindergarten. It was during these years in elementary school that Mayumi became close to Sōma and developed a crush on him for his cool personality. Mayumi would frequently visit Restaurant Yukihira after school, becoming one of its numerous regular patrons. She also would often participate as a judge for the numerous cooking duels held between Sōma and his father, Jōichirō Yukihira.
Main article: Introduction Arc
Mayumi became the judge of the 489th cooking duel between Sōma and Jōichirō. In the end, she declared that Jōichirō was the winner. Though Sōma was upset with his 489th consecutive loss, Mayumi complimented his dish. Sōma took the opportunity to ask Mayumi if she would be willing to try out his newest prototype dish: Grilled Squid Tentacles Dressed in Peanut Butter. Mayumi laughed at the concept, calling it bad. Even though Mayumi did not agree to eat it, Sōma immediately shoved a sample into her mouth, causing her to hallucinate the image of a squid groping her.
Unfortunately, this was Mayumi's last encounter with the Yukihira Family as Restaurant Yukihira closed down for a couple years as Jōichirō left to work overseas while Sōma transferred to Tōtsuki Culinary Academy.
The Karaage Wars
Main article: Karaage Wars Arc
Over the first two months Sōma spent at Tōtsuki, Mayumi had stopped by Restaurant Yukihira every day. Each day the restaurant remained as empty as it had been since the departure of the Yukihira family. Aki Koganei chided Mayumi for not confessing her feelings for Sōma before he left for school. However, much to her surprise, Sōma had returned home for a long weekend to air out the restaurant. As he worked the restaurant by himself, Mayumi felt that a considerable distance between them had formed while he was away at school. During the first night of Sōma's return, Yūya Tomita told Sōma about a Karaage store, Mozuya, that was sapping away customers from the Sumiredōri Shopping District. Sōma resolved to combat this new threat to his hometown and Mayumi wanted to help, but was too shy to ask. Thanks to a literal friendly push from Aki, Mayumi volunteered to be a taste tester for Sōma, which would give her some one-on-one time with him. Unfortunately, Sōma called up a classmate, Ikumi Mito, to assist him. Mayumi was immediately overwhelmed by Ikumi's natural beauty and aggressive personality. Nevertheless, the team was set and their first order of business was to investigate the competition.
At Mozuya, Mayumi, Sōma, and Ikumi got to taste their Karaage and was impressed by the depth of flavor. Returning to Restaurant Yukihira, the crew began their development of their own karaage dish to counter the competition. Although Sōma's first prototype was delicious to Mayumi, he still felt like it was not enough. Sōma asked Mayumi for ideas, which she suggested to make it reflect the shopping district. By the next day, they had yet to make a solid dish, however thanks to a passing group of students, Sōma had finally devised a way to battle Mozuya's karaage with a karaage of his own; making it portable since Mozuya's karaage was meant to be eaten at home rather than fresh in the store. Mayumi came up with the idea to use skewers, but Sōma felt that the idea was a little too common to make a serious impact. When Sōma left to fetch some notebooks from his room, Mayumi was left alone with Ikumi. Mayumi complimented Ikumi, calling her amazing, though Ikumi felt that there were a lot of useless people at Tōtsuki, though Sōma was not bad. Before she could ask further, Sōma had returned. Thanks to some input from Ikumi and a surprising inspiration from a failed idea from Yūya, Sōma finally had a solid idea that was to be implemented the next day. Mayumi resolved herself to help out Sōma as much as she could.
In just a few short days, the Shopping District saw a sharp raise in customers while Mozuya suffered a heavy drop. The Sumire Karaage Roll was a huge success, reviving the previously dead shopping district. With the crisis averted and the week at its end, Mayumi was saddened to know that Sōma was going to leave again. However, Sōma asked Mayumi to work part-time at Yūya's store due to his belief in her reliability based on when they were in school together. Happy to know that Sōma had always noticed her and that she could still help him out while he was gone, Mayumi happily took on the job of making the Karaage Roll while he was away. Much to her joy, Sōma promised to treat her to something nice the next time he comes home.
The 43rd Annual Tōtsuki Autumn Election
Main article: Tōtsuki Autumn Election Arc
Mayumi made a small cameo during the Autumn Election as Sōma began to craft his dish for his 43rd Annual Tōtsuki Autumn Election Quarterfinal Match. He wondered how Mayumi was doing back at Sumiredōri.
- The name Mayumi means "real, genuine" (真) (ma), "reasuon, case, cause" (由) (yu) and "beautiful" (美) (mi).
- Mayumi's surname Kurase means "warehouse" (倉) (kura) and "swift current, rapids" (瀬) (se).
- It can also mean "shoal cellar".
- Mayumi is the only major character in the story not affiliated with Tōtsuki Culinary Academy directly in any manner.
- Mayumi has a keychain of a squid attached to her bag which can be seen at the start of Episode 17.