Mio Ibuki

Mio Ibuki is a student and one of the representatives of class 1-C along with Kakeru Ryūen.

Not only does she possess excellent academic qualities, but her physical ability is also not to be underestimated. She is skilled in combat, having the knowledge of several martial skills that can rival those of many martial artists.

Appearance
Mio is a teenage girl of average height with purple eyes and short blue colored hair. She is usually seen wearing the school uniform with a blue bowtie and orange shirt. Like all the other first years, she wore the red tracksuit over the special island exam period.

Personality
Mio rather prefers acting alone to socializing, which is one of the reasons why she is often isolated in her class.

Unlike her peers, she doesn't seem to enjoy the violence inflicted on others as shown when she flinched after Kakeru smashed a glass bottle on the head Daichi Ishizaki or when Albert Yamada was ordered to beat Daichi and the others for their failure in attempting to get Ken Sudō expelled. She made it clear that she disapproved of their cruelty and wanted them to stop their actions.

She doesn't like being insulted as demonstrated when she told off Kakeru for treating her like a plaything when he made advances on her. She appears to not like being pitied as shown when she angrily slapped away the hand of Kiyotaka Ayanokōji despite him trying to help her up after she was knocked to the ground.

Due to her time with Kakeru, she has come to expect mistrust or deception and even accusations towards herself. She told off Kiyotaka and his group to leave her alone when they enquired about her. However, she is capable of being surprised, like when people actually give her the benefit of the doubt, shown as she was caught off-guard when Kiyotaka stated he trusted her after some panties were stolen from the girl's tent during the island exam. She was so shocked at his belief in her that she nervously blushed while thanking him for it. She was also seen curious, when Kikyō Kushida and Haruki Yamauchi commented on how incredibly close Suzune Horikita and Kiyotaka were lately.

She is very deceptive as it turned out she infiltrated D-Class to steal the key card from Suzune while she was cleaning herself off, despite the class showing her kindness by taking her in and providing food and other necessities. She showed no remorse in stealing the card, even defeating Suzune in a fight.

Physical Abilities
Mio is seen to be an able fighter, however, she is not as strong as Kakeru who dodges her attacks and overpowers her easily. In the special island exam arc, she defeated Suzune in combat, however, it was not clear who would had been stronger if Suzune had not been running a fever.

Plot
Mio Ibuki made her debut sitting at the karaoke bar of Keyaki Mall, where she is seen flinching after Kakeru Ryūen smashed a glass bottle over Daichi's head.

She is later seen with Kakeru and his henchmen after failing to get Sudo Ken of class D expelled. She looks away as Albert proceeded to beat up Daichi again for failing in his attempt to expel Ken.

During the school cruise, Mio confronted Kakeru and demanded him to stop his actions, but he disregarded her words and told her to come back to his room while putting his arm around her. Disgusted by him, she slapped away his hand and demanded him to take her words seriously but was ignored as he walked away. When she tried to stop him, Albert intervened, in which she called him a puppet for following his every order and tried once more to speak to Kakeru but Albert pushed her against the rails telling her to stop. Kiyotaka came to help her up before she angrily slapped his hand away and chastised him not to get involved in her business and stormed off.

During the survival test, Kiyotaka, Airi Sakura and Haruki found Mio injured. She had bruises on her face and was slumped against a tree. Mio was taken back to class D's camp by the group despite protesting that they were enemies during this test.

The morning after the underwear theft incident, Mio approached Kiyotaka as he was working on pitching up the guys tent. She stated that she finds the theft unforgivable and tells him that she is aware that people like Ken would believe she was the one behind it because she was an outsider. Mio stated she knew Kiyotaka holds the same belief but he surprised her by revealing that he trusts her, his reply catches her by surprise. She thanked him and blushed nervously. Since then, she was seen becoming more curious about Kiyotaka's relationships with other people, turning around and stealing glances when Kikyō and Haruki both commented on how incredibly close Suzune and Kiyotaka were lately. While doing so, she caught a glimpse of the leader card in Suzune's possession. Since her camera had been mysteriously destroyed, she managed to steal it while Suzune was taking a bath by herself in the waterfall, after Haruki poured mud on her.

Shortly afterward, somebody started a fire at camp, burning the survival test manual leading to even more trust problems within D Class. Mio used this as an opportunity to sneak away from the camp.

Suspecting that the incident was Mio's doing, Suzune searched for her and found out that she stole the leader's key card. Mio attacked Suzune despite the rules prohibiting violence against students from other classes knowing that as long as nobody noticed, she could get away with it. Taking advantage of Suzune's fever, Mio defeated her and brought the leader card to a student who requested evidence.

It was later revealed that Kiyotaka had deduced that Mio was a spy sent from class 1-C. Kiyotaka was also the one who found Mio's hidden camera and two way radio in which he saw Kakeru possessing the same one as hers the other day at the beach, deducing that he had not left the island and was lying hidden somewhere until the test was over. Kakeru had it all planned out to deceive everyone to gain the most points for his class in the test. Kiyotaka then begun to stage certain events so that Mio could find out who the D-Class' leader was, so she could fulfil her mission and leave them. Kiyotaka had planned to change leaders for class 1-D after classes 1-A and 1-C have verified for themselves that it was definitely Suzune's name on the card. Kiyotaka then executed his final plan, after Suzune's health deteriorated to the point that it became a valid enough reason to change leaders for their class. After the island test was complete and C-Class came last, Mio apologized to Kakeru about incorrectly guessing class 1-D's leader (although she was right but Kiyotaka had changed leaders without her knowledge), in which he forgave her as he recognized that someone has outwitted them, leading to their loss and class 1-D's victory.