UAI get it. Kirishima's pain over not being able to do anything... and Todoroki's regrets over having Bakugou snatched away before his eyes. I regret it all too. Still... this is no time to let our emotions get the better of us.
Mezou is very tall, with hair that swoops down in front of his face. He wears a mask that covers all his features below his eyes. He has 6 arms. It is shown that Mezou's arms are very physically strong.
Despite his frightening appearance, Shouji is a very friendly and gentle person who will work nicely with anyone. Mezou isn't the type to hold grudges, as even when Fumikage's rampaging Dark Shadow harmed him, Mezou held no ill will towards Fumikage.
He is shown to be empathetic and understanding, like when he sympathized with the wishes of his classmates to save Bakugou. He is shown to be willing to risk dying to help Fumikage when he needed it. However, he is emotionally stable also, and able to control his emotions, as despite his own frustration and regret, he understood that going to help Bakugou would put the Pro-Heros plans at risk, and as such, was against mounting a rescue.
He is among the applicants who was participating in the exam.
Mezou places 14th in the Obstacle Race, allowing him to participate in the next event, the Human Cavalry Battle. Minoru asks him if he could team up with him, which he allows. After the Human Cavalry Battle starts, Mezou and his team attack Izuku's team, carrying Minoru and Tsuyu on his back while hiding them with his tentacles. After Minoru orders Mezou to attack, Mezou begins charging at Izuku and Shouto's teams, but Denki releases a huge amount of electricity, electrocuting Mezou and his teammates and become stunned as a result, unable to move. Shouto then freezes Mezou's legs, stopping him in his tracks.After the Human Cavalry Battle ends, Mezou and his team fail to qualify for the final event.
Mezou along with his class watches the closing ceremony of U.A.'s Sports Festival.
Two days after the Sports Festival, Mezou is in class. During the Hero Informatics period, Class 1-A has to decide on Hero names. Mezou writes down and reveals his Hero name: Tentacle Hero Tentacle (触手ヒーロー テンタコル Shokushu Hīrō Tentakoru?).
After Class 1-A is finished formulating their Hero names, Mezou is given a list of 40 workplaces in order to choose a workplace that he wants to train at. On the day of the workplace training, Mezou is at the train station with his class so that he can travel to the workplace of his choice by train.
Back in class, Izuku reveals the content of the exercise test to the class, much to Denki and Mina's happiness; Mezou notes that they are happy because they don't have to adjust their Quirks for real life opponents. On the day of the exercise test, Mr Principal reveals that Class 1-A will be fighting against U.A.'s teachers for their exercise test. Mezou is paired with Tooru and they must face Snipe in their test exam.
Mezou, Tooru and Snipe arrive in an uninhabited city where their test exercise will take place. Crack Shot explains the 30-minute test; Mezou and Tooru must either handcuff him or one of them must escape the battlefield within 30 minutes in order to win and pass the test. The test begins.
After a difficult battle against Snipe, Mezou along with Tooru pass the practical test.
Back in class at U.A., Mezou learns that he passed the written test and will go with his classmates to the forest lodge which is a boot camp. Mezou along with his class go to Kiyashi Ward Shopping Mall to buy necessities for the forest lodge.
The next day after the shopping trip, at U.A., Shouta informs Class 1-A that the destination for their lodge trip has been changed and the new destination will only be announced on the day of the event. The first semester has come to a close and summer break has begun.
On the day of the event, Class 1-A boards a bus that will take them to the forest lodge destination. An hour later, Class 1-A’s bus stops for a restroom break. However, Class 1-A notes that Class 1-B isn’t at the rest stop. Suddenly, two females wearing cat-like costumes and a small boy appear; the females excitedly introduce themselves as the professional Hero Team, The Pussycats. The black haired female explains to Class 1-A that they will be staying at the base of a mountain which is a part of their domain; they have three hours to reach the base of the mountain using their Quirks as they please and those who don’t arrive there by 12:30 pm won’t be served lunch. Soon, Class 1-A realize that they have already arrived at their destination and their training camp has already begun with the Pussycats being their supervisors. Some of Class 1-A try to leave, but Pixiebob uses her Quirk to create a landslide of dirt that causes Class 1-A to fall into a forest called Forest of Magic Beasts, which they must traverse to reach their destination. Suddenly, Class 1-A are confronted by a beast; Kouji tries using his Quirk to control the beast but it does not work due to the beast being made out of dirt. Izuku, Shouto, Tenya and Katsuki mobilize and use their Quirks to destroy the dirt beast.
After Izuku, Tenya, Shouto and Katsuki destroy the dirt beast, Class 1-A begins traversing the Forest of Magic Beasts. However, the journey through the forest to the Cabin takes around about 8 hours. Class 1-A arrive at the facility, battered and tired. It is now 5:20 pm in the evening. Pixiebob admits that she thought they would take longer to get to the facility; she praises Class 1-A for figuring out her Earth Beasts quickly and easily. Class 1-A fetch their luggage from the bus and put it in their rooms. Class 1-A go to the dining hall to have dinner. After finishing eating dinner, Class 1-A go to the hot springs. The next day at 5:30 AM, Class 1-A are outside the training camp cabin. Shouta greets his students and tells them that they will undergo reinforcement training to strengthen and upgrade their Quirks which will also allow Class 1-A to obtain their temporary licenses.
Mezou along with his class undergo training to improve their Quirks.
On the night of the third day of training, Mezou is paired with Fumikage for the test of courage. During the test of courage, the League of Villains Vanguard Action Squad begin their attack by filling the forest with poisonous gas. One of the villains part of the squad called Moon Fish ambushes Fumikage and Mezou. Mezou covers for Fumikage but loses one of his tentacles in the process. They manage to retreat from Moon Fish. However, the ambush causes Fumikage to lose control of his Quirk. Mezou saves Izuku from Dark Shadow's claw and explains the situation to him. They turn their attention to Fumikage; Fumikage has been restrained by Dark Shadow, who is now larger and more ferocious due to the power of darkness. The empowered and berserk Dark Shadow begins taking control of Fumikage’s body. Struggling, Fumikage pleads Izuku and Mezou to run away from him otherwise they will die. Izuku watches in shock.
The rampaging Dark Shadow attacks and destroys several trees around it. Dark Shadow attacks Mezou and Izuku, but Mezou is able to dodge in the nick of time. After maneuvering behind a tree, Mezou sees that Dark Shadow attacks anything that moves or makes, while also noting that Fumikage’s regret and indignation is intensifying Dark Shadow’s control over Fumikage as well as its own power. Fumikage pleads Mezou and Izuku to save the others and forget about him. Mezou informs Izuku that they need light to calm Dark Shadow down so that Fumikage can regain control; he tells Izuku that he can distract Dark Shadow while he runs back to the facility for help; Izuku is indecisive due to wanting to save Katsuki as well. Before Izuku can reply, Dark Shadow strikes at them, but Mezou is able to evade. Seeing that their situation is desperate, Mezou tells Izuku that he can either save Fumikage with him or save Katsuki by himself. Izuku apologizes to Mezou because he cannot make that decision and says that he has a plan. Mezou and Izuku arrive to where Katsuki and Shouto are along with Dark Shadow in pursuit, with Mezou asking one of them to make light. Before he can explain further, Moonfish senses Mezou and Izuku’s presence and sends one of his teeth to attack them. The rampaging Dark Shadow uses its enormous claw to crush Moonfish, destroying Moonfish’s teeth and knocking him out. Shouto and Katsuki are surprised at what happened. Izuku’s plan was to lure the rampaging Dark Shadow to their location by creating decoys from Mezou’s Replicant Arms which worked. Izuku is happy to see Katsuki, glad that he doesn’t have to save only one of his classmates and sacrifice the other.
After the rampaging Dark Shadow effortlessly defeats Moonfish, Shouto and Katsuki use their Quirks to calm down Dark Shadow, returning Fumikage to normal. Now back in control, Fumikage thanks Katsuki and Shouto for saving him. Mezou is glad that Fumikage is fine. However, Fumikage is regretful that he couldn’t conceal his anger when Mezou lost one of his arms, which caused him to release Dark Shadow out of anger and lose control due to being enraged and spurred on by Dark Shadow’s own rage. Fumikage is guilty for harming Mezou; Mezou tells Fumikage that he doesn’t need to feel guilty and shows no ill will towards Fumikage.
Izuku tells Fumikage that their top priority is to protect Katsuki, who is the target of the villains’. Izuku decides that they should escort Katsuki back to the facility and take a shortcut through the forest; Izuku thinks that with the power of Mezou’s scouting capabilities,Shouto’s powerful Quirk and the unrivaled power of Fumikage’s Dark Shadow, escorting Katsuki will be a cinch. However, Katsuki is angry that he needs protecting and refuses their help. The Bakugou Escort Squad (consisting of Mezou, Shouto, Izuku and Fumikage) begin escorting a begrudging Katsuki back to the facility. The Bakugou Escort Team travels to the facility and comes across Ochako and Tsuyu. When Ochako and Tsuyu notice that Katsuki is hot with them, Izuku, Mezou and Shouto turn around and see that not only Katsuki has disappeared but Fumikage as well. After the masked magician-like villain reveals to be the one who took Katsuki, Izuku demands that he give Katsuki back.
After handing Kousei to Ochako, Shouto attempts to stop Mr. Compress by trying to freeze him with his ice attacks, but Compress's speed allows him to avoid Shouto's attacks. Mr. Compress also reveals that he captured Fumikage as well due to being impressed with his victory against the powerful Moonfish and states that he will be very useful, much to Izuku's anger. Compress begins escaping. Izuku hatches a plan to save Fumikage and Katsuki; Izuku asks Ochako to make him, Shouto and Mezou float, then tells Tsuyu to use her tongue to throw their weightless bodies as hard as she can towards the magician, which will allow the three of them to fly towards the villain with Mezou using his arms to guide their trajectory; once they are in reach of the villain Ochako will deactivate her Quirk. However, Ochako and Shouto see that Izuku’s injuries are severe and think he should stay put. Izuku insists that he goes along which convinces Ochako and Shouto. They execute the plan; Tsuyu wraps her tongue around Izuku, Mezou and Shouto while Ochako uses her Quirk to make them weightless. Tsuyu throws the weightless Izuku, Mezou and Shouto towards Mr. Compress. The three fly at Compress at high speed and reach him. Ochako deactivates her Quirk, causing them to land on Compress and smash him onto the ground. Izuku, Mezou, Shouto and Compress landed right at the Vanguard Action Squad's rendezvous point. After apprehending Mr. Compress, Izuku, Shouto and Mezou see that they are right in front of Dabi, Himiko and Twice.
Dabi launches his flames which hits Mezou's arm and injures it. After Himiko attacks Izuku, Mezou smacks her away from Izuku. Mr Compress prepares to give Dabi the captured Fumikage and Katsuki, only to find that the marbles are not in his pocket. Mezou reveals that he took the marbles from Mr Compress. As Izuku and Shouto prepare to backup Mezou, Kurogiri arrives and blocks their path. After Himiko, Twice and the Noumu escape, Mr Compress reveals that the marbles Mezou took are not the captured targets and are decoys instead; the marbles Mezou took transform into ice, which shocks Mezou. Mr Compress removes his mask and sticks out his tongue which has the actual marbles. Having overheard what is happening; Yuuga takes action and fires his Navel Laser at Mr Compress’s face, which breaks Compress’s mask and causing Mr Compress to spit out the marbles containing Fumikage and Katsuki.
Izuku, Mezou and Shouto rush to grab the marbles, although Izuku starts succumbing to his injuries which causes him to fall to the ground. Mezou and Shouto continue rushing towards the marbles; Mezou grabs the marble containing Fumikage, thus saving him. Shouto is almost in reach of the marble containing Katsuki and nearly grabs it, but Dabi snatches it away before Shouto can grab it.
Mr Compress deactivates his Quirk, freeing Fumikage and Katsuki. Mezou, Shouto, Izuku and the freed Fumikage see that Katsuki has teleported away with the Vanguard Action Squad.
After the Vanguard Action Squad leave, the training camp ends and Mezou returns home. Two days later, Mezou visits Izuku in the hospital and hears about Eijirou and Shouto's plan to rescue Katsuki. As Tenya orders them to stop thinking about such an attempt, Mezou stops Tenya. Mezou understands Eijirou and Shouto's frustration in not being able to save Katsuki and advises that they should not make the decision based on their feelings. Mezou leaves Izuku's room after the doctor requests them to.
Quirk and Abilities
Dupli-Arms (複製腕 Fukuseiwan): Mezou's Quirk allows the tips on his tentacles to replicate parts of his body (ex. mouth, ears). Mezou can also use his tentacles to make duplicates of his body parts such as an extra arm and can use them as decoys.
Enhanced Strength: Mezou has shown to have great physical strength as he was able to exert as much as 540 kilos of force during the Quirk Apprehension Test. He was able to carry both Tsuyu and Minoru on his back without any difficulty.
Minoru admires Mezou for his octopus appearance and tall height. During the fight between Izuku and Shouto in the Sports Festival tournament event, Mezou prevents Minoru from being blown away.
Mezou is on good terms with Fumikage, During the training camp, he and Fumikage were attacked by Moonfish. Mezou protected Fumikage but lost an arm in the process. Angered that Mezou sacrificed a limb just to save him, Fumikage (enraged by his incompetence and the influence of the night's darkness) lost control of Dark Shadow which caused him to harm Mezou. Mezou resolved to save Fumikage alongside Izuku which they eventually succeeded. Fumikage felt regret for harming Mezou and apologized to him. Mezou shows no ill will towards Fumikage, thus he and Fumikage are on good terms with each other.
They were partnered with each other during Battle Trial Arc. Mezou and Shouto along with Izuku worked together during the training camp in order to save Katsuki and Fumikage.
- Mezou is student No.11 in Class 1-A.
- He ranked 6th during the Quirk Apprehension Test.
- His name comes from "壁に耳あり障子に目あり" (Kabe ni mimi ari shōjinimeari? lit. "walls have ears, doors have eyes").
- He likes takoyaki.and squid ink pasta.
- According to Horikoshi, Mezou is fun to draw.
- (To his classmates, regarding Katsuki Bakugou's kidnapping) "I get it. Kirishima's pain over not being able to do anything... and Todoroki's regrets over having Bakugou snatched away before his eyes. I regret it all too. Still... this is no time to let our emotions get the better of us."