""I will avenge my brother!""

- Yumi Ogura

Yumi Ogura (小椋 由美, Ogura Yumi) was one of the students of 9th Grade Class 3 in 1998. She and Takako Sugiura assisted Izumi Akazawa in her duties as the head of countermeasures, acting as her right and left hands. She was in the Drama club with Aya Ayano and Izumi.

Yumi was a slightly tanned girl of below average height. She had shoulder-length brown hair with a pink hair clip and light golden-brown eyes.

She was usually seen wearing the Yomiyama North girls' school uniform. She was one of the few main characters not seen outside of school, so her casual clothing is never shown.

Yumi seemed to be shy, as she didn't talk much and was very quiet. She was concerned about Class 3-3's countermeasures, working with Izumi and Takako. Yumi was a calm, gentle, quiet, and innocent girl, contrasting with Izumi's harsh personality and Takako's cold demeanor. She often blushed.

Yumi was good friends with Aya Ayano, as well as Junta Nakao and Takako, with whom she often spent breaks. She was also very close to her reclusive brother, Atsushi.

Her brother's and Aya's deaths devastated Yumi and caused her to lose her sanity. She developed a strong hate towards Mei Misaki, blaming her for their deaths and wanting to avenge them. She followed Takako over the edge and attempted to kill Mei in Episode 11, which only led to her own death.

In the manga, Yumi isn't hostile towards Mei after the class stops ignoring her and Kōichi. She and another girl later talk with Mei, much to Kōichi's shock. It could be that they were on more friendly terms.

In the novel, Yumi is a quiet, calm girl with an open mind. She is on good terms with Mei and Takako and has a somewhat neutral relationship with Izumi.

In the film, Yumi is shy and very quiet. She rarely speaks and isn't seen much. It is unknown if she is on friendly terms with Takako and Izumi. She also panicked when the inn was set on fire, attempting to run but falling onto the floor. This causes another student to fall from the second floor to his death. She still ignores Kōichi and Mei, even when the rest of the class stops ignoring them.

Yumi was present for Kōichi's first day of class ("Rough Sketch"). She stood off to the side, talking to Junta Nakao and Takako, rather than welcoming her new classmate like her friend Aya. Yumi was also present for Mr. Kubodera's suicide, but wasn't among the group to leave right away; she's seen on her knees on the floor in shock at the situation before pulling herself together and exiting the classroom.

In "Body Paint", Yumi and Aya met Kōichi and Naoya Teshigawara in front of the old school building, looking for Tatsuji Chibiki for some acting advice. Later, when Aya and Yumi part ways, Yumi continued home and found the front of her house had been crushed by an excavator. Her brother, Atsushi, was found dead in his room. At roughly the same time, the Ayano's car was hit by a falling rock and went over the side of the mountain, killing Aya and her parents. Both losses devastated Yumi.

In "Glass Eye", she went on the class trip and sat with Izumi and the other girls at dinner. She was present when Izumi blamed the calamity on Mei, but like Takako, she did not actually take part in the shouting match that followed.

In "Makeup", Yumi heard the tape played by her countermeasures partner, Takako. She was shocked and enraged at the news. Taking a knife from her room, she set out to kill Mei, declaring that she would avenge her brother. Driven by revenge, the normally quiet Yumi led the hunt for Mei and Kōichi, forcing Kōichi to hit her, knocking her back into Kyōko Kaneki and making both girls fall, something Kōichi apologized for as he ran away.

Furious, Yumi and the others continued pursuing the two into one of the inn's rooms. Yumi ordered her fellow students to step aside before kicking the door in and following Mei and Kōichi onto a slippery window ledge. While attempting to kill Mei with the knife, Yumi leaned too far as she swung her knife and lost her balance, falling to the ground and breaking her neck. She died instantly on impact, her body bent at an unnatural angle.