Masaki Mizushima/Synopsis

Vigilantes Beginnings Arc
After a sudden villain outbreak, where several innocent people were turned into Instant Villains, Eizo Tanuma organizes a meeting with several of the heroes. In addition to Manual, Best Jeanist, Shota Aizawa, Death Arms, Snipe, Thirteen, Endeavor, Airjet, Midnight, Ingenium, and Gunhead were called into the meeting.

Together, they spoke about the victimized civilians injected with the Trigger drug and how to help the unwilling civilians injected with the drug. After the meeting, the heroes returned to their daily duties.

Sky Egg Arc
On the occasion of Captain Celebrity's return to the United States, Makoto Tsukauchi decides to organize a farewell show at the Tokyo Sky Egg, inviting several of Japan's most famous heroes to participate. Manual is one of them.

However during the event, the Tokyo Sky Egg is attacked by creatures known as Bombers, sent there by villain Number 6 to assassinate Captain Celebrity. Manual is one of the heroes who did not go out to fight the creatures but stayed inside to reassure the spectators and help keep calm during the crisis

In retaliation for the heroes' intervention, Number 6 causes a Bomber to self-destruct in a large explosion, causing the building to collapse. Fortunately, All Might arrives in time to avoid catastrophe, saving thousands of lives.

Vs. Hero Killer Arc
Following the U.A. Sports Festival, Manual sent Tenya Ida an internship opportunity at his very own Hero Agency in Hosu City. Tenya accepts, and on the first day of their field training, Manual takes Tenya out on patrol. He tells Tenya that he is very excited to be mentoring Ingenium's younger brother, and is confused as to why Tenya would not have chosen a more famous hero to intern with.

When they return to Manual's office at night, he tells Tenya that the city remains on high alert so the criminals have been reluctant to come out. When they patrol Kyoto together the next day, Manual admits that he knows Tenya only chose his agency to avenge his brother.

The Hero Killer: Stain attacked Ingenium in Hosu City, and Manual was able to deduce that Tenya only wanted to intern in Hosu to go after him. He says that he's glad Tenya chose his agency, but he also informs Tenya that he shouldn't be pursuing personal grudges. He goes on to lecture Tenya about the regulations on Quirks, and states that a hero must not use their Quirks for themselves because if they did, it would be a very serious crime. Tenya replies that he understands, and so Manual lets it go and they continue patrolling.

When chaos ensues in Hosu and buildings start going up in flames during their patrol, Manual receives a message that villains have appeared in the city. He responds and decides to head to the battle zone himself. He tells Tenya to accompany him, but does not notice that he has run off by himself until he arrives at the center of the destruction.

Manual and several other Pros face off against the culprits, two Nomu with incredible strength. With just the two of them, the Pro Heroes have their hands full. Manual notices Tenya is missing and calls out to him, but is forced to put his focus on fighting the fires created by the monsters. During the battle between the heroes and the monsters, Manual notices one of them about to crush a fellow hero. He calls out to her, but Endeavor arrives to save the day.

Once the chaotic incident finally ceases, Manual and Gran Torino visit Tenya, Shoto Todoroki and Izuku Midoriya at the hospital. The three of them managed to defeat the Hero Killer but were still liable to repercussions. Police Chief Kenji Tsuragamae explains all six of them including Endeavor would be punished if the incident went public.

However, Kenji allows the incident to remain confidential and thanks the boys instead. Afterward, Tenya takes a moment to apologize for neglecting Manual's advice. Manual sheds a tear, knowing he has to take responsibility as a supervisor for his negligence. He chops Tenya in the head, telling him to never do it again.

Endeavor Agency Arc
Due the increase of the villain activity, The Public Safety Commission demand all the students heroes for all academies to undergo practical field training, restarting the Hero Work-Studies program. During this second round, Manual employees Tenya once again.

Later, Tenya reveals that Manual is leading a team in Hosu, and thanks to the experience he gained during his Work-Studies with him, he has learned the art of being flexible.

Paranormal Liberation War Arc
By the end of march, Many Heroes across Japan are rallied by the Hero Public Safety Commission to take down the recently formed Paranormal Liberation Front with the merge of the League of Villains and the Meta Liberation Army. They have info about the main hideouts of the villain organization thanks to Hawks. Manual is assigned to the Jaku General Hospital raid team along with several other Pro Heroes and lead by Endeavor.

At Endeavor order, the raid begins. While one group are in charge of evacuating patients, visitors and hospital staff from the building, another group is in charge of arresting Garaki, although the situation gets complicated when he releases a horde of Nomu to escape to his secret laboratory to awakes Tomura from his stasis.

In spite of everything, the heroes defeat the creatures and assault the laboratory, preventing Dr. Garaki from awakening a Tomura Shigaraki. Facing his defeat, a heartbroken Dr. Garaki declares that the Devil's Dream has finally ended. However, against all odds, Tomura Shigaraki awakens, despite having previously verified that his heart was not beating. Seeing the situation, he immediately uses his Decay, which spreads rapidly through the laboratory, disintegrating everything in its path.

Ryukyu manages to grab Manual and get him out of there along with a few heroes before the building completely disintegrates. The decay way spreads to the nearby city, killing dozens of heroes on its way. When Tomura surfaces, several of the surviving heroes, such as Endeavor, Ryukyu, Gran Torino, and others confront him. Also the students Izuku Midoriya and Bakugo Katsuki confront him. However, Tomura is much more powerful than before, having several Quirks, including Super Regeneration.

Manual also helps as he can in the fight. In the lab escape, Eraser Head ended up with a totally shattered leg. That is why Manual, along with Rock Lock, keeps him standing so he can make use of his Erasure on Tomura, so he can't use his Quirks. Manual also uses his Quirk to wet Eraser Head's eyes so he can keep them open and on Tomura, which the Erasure Hero thanks him for.

Even with his Quirks nullified and outnumbered, Tomura turns out to be an extremely powerful enemy, and the heroes have great difficulty defeating him. In addition, Tomura is constantly moving to prevent Shota from continuing to nullify her powers. Therefore, Manual and Rock Lock carry Eraser Head to Tomura's locations as the latter tells the former to adjust his water flow accordingly.

Having enough of Shota's interventions, Tomura first throws a Quirk-Destroying Bullet at him, striking him in the left leg, causing Shota to quickly cut it off before the drug could spread throughout his body. Then, Tomura decides to attack him, so Manual and Rock Lock rush to get him to safety, but Tomura is much faster and digs his fingers into Shota's face. Izuku yanks Tomura back with Blackwhip, but he manages to injure Shota, causing him to finally stop using his Erasure on him. With this, Tomura can use all his Quirks again, healing in an instant from all his injuries thanks to the Super Regeneration.

Manual and Rock Lock quickly try to stabilize Eraser Head's severed leg to stop the bleeding, while Izuku faces Tomura. Despite being able to use his Quirks again, Tomura's body reaches its limit and begins to rip, so he decides to use his Decay to end the fight once and for all, but Izuku jumped into the air carrying everyone with Blackwhip. Realizing that his control of Blackwhip is destabilizing, Izuku puts down Manual and the other heroes down so he can face Tomura in the air and barrage him with full powered attacks. However, despite his best, Izuku was also reaching his limits as the Regeneration Quirk from Tomura was turning the battle into a war of attrition. Fortunately. Endeavor, aided by Katsuki and Shoto, boosts up in the air and grabbed Tomura from behind before unleashing the full blast of Prominence Burn, burning Tomura to a crisp.

Suddenly, Tomura's body was taken over by All For One who subsequently impales both Endeavor and Katsuki, sending Izuku into a furious rage that lowered his guard down, allowing Tomura to finally touch Izuku and claim his prize: One For All. Unfortunately, Tomura had failed to steal One for All from Izuku due to his body being incomplete and the strong willpower of both Izuku and the predecessors. While Manual continues to give first aid to Shota, he was subsequently surprised that his former intern, Tenya, arrived with more reinforcements, informing them that Gigantomachia is rampaging across Jaku City to get to Tomura. Manual proceeds to help escort the injured Shota and Ryukyu off the battlefield.

Unfortunately, it was too late as Gigantomachia arrives with the League of Villains in his back. Luckily, Gigantomachia ends up eventually collapsing from the sedative anesthesia he ingested after his battle with Class 1-A and 1-B. With Best Jeanist and Lemillion entering the battle, the tides have turned for the heroes to subdue the League of Villains, but unfortunately, Tomura, along with the remaining League members, successfully escape the battle with the Near-High End Nomus used to distracted the heroes, forfeiting the battle.

U.A. Traitor Arc
In the aftermath of the Paranormal Liberation War, All For One has escaped from Tartarus, and proceeded to break into several more maximum security prisons, liberating the inmates. Due to the chaos inflicted by Gigantomachia and the mass breakout of prisoners, the whole country entered a state of total chaos and anarchy. In addition, many heroes resigned and called it quits because of the massive criticism of their work, and the destruction spreading unchecked. Manual is one of the few heroes remaining and does his best to stop the villains and apprehend them as much as he can.

Final War Arc
With the upcoming battle for the Final War, Shota has devised a plan that will lure All For One out of hiding. Taking advantage of All For One's spy, Yuga Aoyama, they manage to get him and his forces to reveal themselves, further catching them off guard by using the Warp Gate Quirk copied by Neito Monoma to teleport the Heroes onto the battlefield, and subsequently warp the Villains to locations all over the country.

Manual is assigned to the now floating U.A. Fortress, which is designed to keep Tomura trapped within, and just like in the previous War, his role is to help moisten the eyes so that they can use Erasure on Tomura, erasing his Quirks. However rather than using it on Shota, who do to losing an eye his Quirk is all but useless, Neito copies Erasure, with Manual using his Quirk to moisten his eyes.

The three are positioned outside of the cage that surrounds U.A., on top of the "observation deck" on the electric powered facility, and when Tomura is warped into the school, they begin the plan. After a brief scuffle between the Heroes inside, Tomura tries to attack, only to find his Quirks not working again. He turns to see Neito using Erasure, who laughs mockingly at the villain, despite Manual telling him to stop moving. Unfortunately, the plan is ultimately failing when Izuku didn't show up to face Tomura because he was caught in a different Warp Gate, teleported to Okuto Island instead, and what's even worse, Tomura begins to sprout a massive blob of fingers which hordes all over the field.

The heroes realize that the horde of fingers Tomura sprouted is not a Quirk but just apart of his "growth", as the result of the Quirk Singularity, due to his body adapting to the ever-evolving Quirks. Manual continues to keep Neito's eyes moisturized while the heroes are giving all they've got to defeat Tomura. However, Manual and the other heroes were devastated when Katsuki is seemingly killed by Tomura when he punched his chest, bursting his heart.

As Katsuki lays dying, Edgeshot enters Katsuki's heart and subsequently performs CPR using his Ultimate Move: Zenith to try and resurrect him, sending Tomura into a furious rage. As the result of the accumulating damage being inflicted by the heroes and the mental deterioration, Tomura undergoes another metamorphosis, transforming his body into a behemoth covered in fingers, decimating the heroes one after another until Izuku finally arrives. Unleashing the full power of One For All, he's able to inflict catastrophic damage to Tomura's body, but despite reaching the brink, he refuses to backdown.

Meanwhile, due to the heavy fighting from Endeavor and All For One, and the fiery battle between Dabi and Shoto, the weather has become even worse as a massive cumulonimbus storm that has started growing over Japan and continues to expand. This causes trouble for Neito, Manual, and Shota, as Manual states that the incoming wind speeds are interfering with his control of the water flow, putting them at risk of Neito blinking or adverting from Tomura once. Despite these harsh circumstances, Neito continues to endure, as he cannot afford to let himself blink once while everyone is giving it all they've got to defeat Tomura. Suddenly, Shota realizes something was off, and he turns around to see they are suddenly caught off guard, as a Warp Gate forms behind them, teleporting Kurogiri and Present Mic.

Manual had just became aware of Kurogiri teleporting behind them, but things get even worse when another portal appears next to them, teleporting Twice Doubles conjured by Himiko Toga that begin to swarm them. Manual tries to attack but he and Shota are immediately pushed to the side, as the Doubles dogpile on Neito, causing him to shut his eyes and undoing Erasure. As a result, Tomura unleashes a massive explosion, destroying most of the U.A. Fortress. With the power line busted and the electromagnetic barrier barely standing, Mandalay then reports in that someone has hacked into their system and they have lost control of the flight system, causing the fortress to start to fall to the ground. She also reports in on the undoing of Erasure due to Shota, Neito, and Manual being attacked.