Yuji Katakura (片倉 優二 Katakura Yūji ) is a math teacher at Seiryou High School and Keiichi Katakura's older brother. Like Keiichi, Yuji is also an extreme sadist, even more than his younger brother. He is a side character in the Nijiiro Days series.
Yuji is a very tall man with a slim frame who wears rectangular glasses. He has short, straight, brown hair which frames his face. He has brown eyes which are of a lighter color than his hair.
For the most part, Yuji is genuinely a really kind, considerate and responsible teacher. He cares a lot about his students and is very serious regarding their future, in which he can be a bit scolding at times. He is also considered very scary when angry or provoked, and behind closed doors, he is an extreme sadist and is very dominant and commanding. He also carries around a whip and sometimes gets into fights with Keiichi.
Yuji Katakura is the oldest of two brothers. It has been stated that Yuji has been a sadist for a while but doesn't like to show this side of his in public. Yuji later became a teacher math at Seityou High School, the same school as Keiichi attends. He also developed a "friendship" with a fellow teacher named Satomi.
Yuji is a teacher at Seiryou High School as well the homeroom teacher of Class 3. He is seen being serious in school regarding his students future and their studies, and becomes quite worried and at the same time scolding when the fail their tests, as in the case as Keiichi, Natsuki Hashiba and Tomoya Matsunaga. After Natsuki had seen Anna Kobayakawa sleeping at Yuji's room in school, he got the impression that they were dating. However, Yuji let Anna sleep there because she often got sleepy due to side effects of medicines, and she later cleared out that they were not dating.
Yuji's younger brother. They get into fights with their whips very often and are always at odds. Yuji is also quite strict with Keiichi and doesn't want him to call him "older brother" at school. Yuji can also be dominant, scolding and commanding towards Keiichi and sees himself as the superior one as he is older, which irritates Keiichi. Despite that, Yuji really cares for Keiichi and wants the best for ― and doesn't want him to get involved with the wrong types. He also looks after Keiichi and doesn't want to hand over him to the types as Satomi-sensei.
Satomi is a colleague of Yuji. Initially, they seemed to be on friendly terms who seemed to know each other well. However, in reality, although they do know each other well as they both are sadists and colleagues, Yuji considers her a "bitchy woman" who is nasty and dislikes her to a degree, likewise with Satomi. Yuji also didn't want Keiichi to get involved with Satomi since he knew her real personality, and both states that they aren't each other's type. Despite that, they agree to take care of each other as colleagues even though they are frequently annoyed by each other.
- Yuji and Keiichi look almost identical.
|Male Characters||Natsuki Hashiba • Tomoya Matsunaga • Keiichi Katakura • Tsuyoshi Naoe • Imagawa • Kakei • Masaomi Tsutsui • Shinsuke Nezu • Taizo Sanada • Usami • Wataru Mochizuki • Yuji Katakura|
|Female characters||Anna Kobayakawa • Aya Ohno • Ishida • Kaori Chiba • Mari Tsutsui • Nabe • Nozomi Matsunaga • Rina • Satomi • Yukiko Asai • Yuri Kobayashi|