Yui Kodai
Yui Kodai is a student in Class 1-B of U.A. High School's Hero Course in the series My Hero Academia. Operating under the hero name "Rule," she is a calm and remarkably reticent young girl characterized by her stoic demeanor and restrained expression. Possessing a versatile Quirk called "Size," she specializes in tactical support by altering the scale of non-living objects. Though highly inconspicuous alongside her more outgoing classmates, she plays a vital supportive role in both practical class exercises and serious battle operations.
Overview
Yui Kodai is a student in Class 1-B of U.A. High School's Hero Course in the series My Hero Academia. Operating under the hero name "Rule," she is a calm and remarkably reticent young girl characterized by her stoic demeanor and restrained expression. Possessing a versatile Quirk called "Size," she specializes in tactical support by altering the scale of non-living objects. Though highly inconspicuous alongside her more outgoing classmates, she plays a vital supportive role in both practical class exercises and serious battle operations.
Appearance
Yui features a distinct black bob haircut. Her hero outfit consists of a red-and-white bodysuit with a white miniskirt, inspired by classic giant light heroes. Her headgear includes a sun visor topped with a fin-like crest. For carrying gear, utility pouches are attached around her waist and across both of her shoulders.
Personality
Yui has an extremely quiet and unflappable personality, maintaining a silent poker face regardless of the situation. Unlike many of her energetic peers, she is low-key and reserved, though not cold or brooding. She frequently communicates using brief vocal sounds rather than full sentences, notably letting out subtle exclamations when eating her favorite food, tomatoes. Her naturally unbothered disposition is paired with an oblivious side, as she completed middle school entirely unaware that a fan club had been formed for her.
Abilities
Her Quirk, known as "Size," allows her to freely manipulate the dimensions of any non-living object she touches. She can shrink massive items down for effortless storage and transport, or suddenly expand smaller objects into large obstacles to block attacks. The ability cannot be used on biological organisms. Deactivating her Quirk involves a hand gesture where she brings her fingertips together. In group combat, she collaborates with her teammates to launch scaled-up objects as wide-range long-distance attacks.
Background
Originating from Shimane Prefecture, Yui entered U.A. High School as a student of Class 1-B. During the U.A. Sports Festival, she competed in the obstacle course and cavalry battle. Later at the forest training camp, she served as a scare actor during the test of courage before being caught in a villain invasion. At the school festival, she took on the role of Juliet in her class's stage play while using her power to manage stage props. In the joint battle training against Class 1-A, she fought in the fifth match using coordinated team tactics, and eventually participated in major operations to hold off massive threats during the final battle between heroes and villains.
Relationships
Yui shares a strong camaraderie with her Class 1-B peers. She relies on class representative Itsuka Kendo, who protected her during a villain gas attack at the training camp. In combat training, she worked closely with Reiko Yanagi and Nirengeki Shoda, combining their respective abilities into a seamless long-range offensive. She also formed a cavalry team with Kojiro Bondo and Manga Fukidashi, and collaborated with Juzo Honenuki during school events. When facing Class 1-A's Ochaco Uraraka in battle, the two demonstrated a subtle similarity in the hand movements used to deactivate their Quirks.
Trivia
Yui is a fond collector of Russian nesting dolls (matryoshka) and has a personal liking for tomatoes. During her middle school years, her quiet charm led her male classmates to form an unofficial fan club for her, though she remained completely unaware of its existence throughout her entire middle school life. Additionally, her hero costume features design elements such as headpiece fins and color schemes that draw inspiration from classic giant tokusatsu superheroes.
