Ken Ishiyama/Synopsis

Entrance Exam Arc
Cementoss first appears as a part of U.A. High's judging panel during the Entrance Exams. He is visually surprised when Izuku Midoriya uses his Quirk to destroy the giant robotic villain in a single punch.

U.S.J. Arc
Cementoss arrives with his fellow faculty members when Tenya Ida brings them to the U.S.J. to halt the League of Villains' assault. He uses his Quirk to create a wall between All Might, Izuku, and Eijiro to protect All Might's identity. He tells Eijiro it's dangerous and commands him to return with his class. All Might thanks Cementoss for this, and Cementoss replies that he's actually a big fan of the number one hero.

U.A. Sports Festival Arc
During the U.A. Sports Festival's final event, Cementoss acts as the proctor for the one on one fighting tournament. He creates the ring where the combatants will fight and a chair for himself to sit. He sits down and warns the participants that he will step in if things get too rough.

During the fight between Izuku and Shoto, Cementoss contacts Midnight and asks her if they should stop their fight because of Izuku's reckless fighting. He adds that his adrenaline is blinding him from how serious his injuries are and that Recovery Girl likely won't be able to heal him in a single session. He also says Izuku may not even be able to fight in his next match even if he wins. They allow the two to continue fighting until the climax of their bout. Worried that the two may kill one another, Cementoss and Midnight step in.

However, Izuku's and Shoto's attacks hit Cementoss's cement pillars, creating a shockwave that destroys the entire arena. After the smoke from the collision clears, Cementoss comments that although great power isn't always a good thing, he finds Shoto and Izuku both amazing.

Vs. Hero Killer Arc
Following the U.A. Sports Festival, U.A. students receive internship opportunities from Pros hoping to draft them. In the faculty room, Cementoss informs All Might that a new nomination has arrived for Izuku.

Final Exams Arc
Prior to Final Exams at the end of the first years' first term, Cementoss meets with his fellow faculty members. They discuss changing the finals format from sfacing robotic villains to fighting against the teachers. Cementoss comments that this may be too difficult for the students, but they all ultimately agree on the change. Cementoss joins the other teachers at the Final Exams practical portion test site to meet Class 1-A. Cementoss is placed against Eijiro and Rikido Sato in the first match.

The three of them arrive in a replica city area where their battle begins. Cementoss begins by using his Quirk to create many cement walls to block their advance from the front. Eijiro and Rikido use their Quirks to smash their way through the walls, but Cementoss continues to create more. As both the student's Quirks work on a limit, Cementoss holds the advantage in a drawn-out battle. Cementoss informs the duo of their weakness as he overwhelms them with cement and knocks them out.

Provisional Hero License Exam Arc
Cementoss, Midnight, and Ectoplasm join Shota Aizawa in his homeroom class to announce that Class 1-A needs to develop super moves. They move to Gym Gamma where the teachers announce that the students will need special moves for the upcoming Provisional Hero License Exam. Cementoss uses his Quirk to create stages for each student to fight one of Ectoplasm's clones.

Endeavor Agency Arc
A few days before Christmas Eve, Cementoss is in the Conference Room, discussing with other U.A. teachers about the Hero Public Safety Commission demand to all hero schools that their students must undergo practical field training. Cementoss does not avoid showing his concern about the Hero Work-Studies starting again so suddenly.

For everyone, it is clear that, after the disaster that occurred in the Deika City, in which it is suspected that the League of Villains was involved, the Commission surmises some kind of huge imminent crisis, and wants all heroes to be ready for what can happen. Cementoss comments that it's the first time that something like this has happened.

For New Year's Eve, the U.A. Staff allows their students to return to their homes for a day, escorted by pro heroes, before starting the Work-Studies. On the morning of New Year's Day, Cementoss picks up Izuku in front of his apartment to take him to the Endeavor Agency.

My Hero Academia: World Heroes' Mission
While Cementoss continued to teach at U.A., a major city suffers from a terrifying terrorist act committed by Flect Turn, the leader of the cult known as Humarise, who detonated a Trigger Bomb in a large city, causing a large number of victims. As a result of this, the World Heroes Association mobilizes a anti-terror joint task force made up of the top heroes worldwide in defeating the terrorist organization.

U.A. teachers Present Mic and Cementoss volunteer to accompany the Japan Task Force which includes members from Fat Gum's agency and Gang Orca's agency. They have the mission of storming the branch that Humarise has in Tokyo, arrest its members and get hold of any Trigger Bombs that might be there. Despite their successful raid, the heroes have failed to locate the Trigger Bombs and the most prominent members of Humarise. Around the world, the other hero teams also succeed in their respective raids, but with the same results. The WHA director orders all the hero teams to stand by in their respective countries.

A few days later, the operation is compromised when Flect Turn hacked into every communications network and broadcast to the world that they have planted Trigger Bombs in the major cities of the twenty-five countries and they will detonate them in two hours. Humarise's ultimatum results in widespread panic and hysteria in Tokyo. The WHA greenlights the heroes being deployed to each sector and fights in defense to quell the chaos and locate the Trigger Bombs.

With major highways and roadways clogged and blocked in a traffic jam, Present Mic also arrives to help along with Cementoss, asking him to use his Quirk to create a path to evacuate people trapped on a highway bridge. Present Mic uses his Voice Quirk to draw the attention of drivers and tell them where to evacuate.

The heroes managed to locate the Trigger Bombs, only to engage in a all-out war against the Humarize sleeper agents guarding the bombs. All the heroes fight relentlessly until the countdown finally reaches zero. Much to their relief, after several seconds pass, none of the bombs go off, indicating that the other heroes managed to defuse the main devices just in time. With the bombs disarmed and the Humarise members arrested, Present Mic and Cenemtoss return to U.A.

Paranormal Liberation War Arc
The months go by until it's late March. Thanks to Hawks, the Hero Public Safety Commission has found out that the League of Villains and the Meta Liberation Army merged into the Paranormal Liberation Front, with Tomura Shigaraki as the main leader. Hawks also informed them about the organization, the hideouts, and the plans of the PLF. With this info, the Commission organized a large force of Pro Heroes, divided into several teams to take down the villain organization.

Cementoss is assigned as a member of a large group of pro Heroes whose mission is to storm Gunga Mountain Villa, the main headquarters of the Paranormal Liberation Front, and arrest all its members. When the raid starts, Cementoss assists his allies by using his Quirk to tear open the Paranormal Liberation Front's Gunga Mountain Villa hideout, forcing many of the organization's followers to come out and fight, but due to the surprise of the attack, the heroes prevail in the first confrontations. Cementoss congratulates his teammates for their stellar work.

As time goes by, PLF soldiers fight more fiercely against the heroes, especially when some of the lieutenants join the battle. Cementoss is knocked down when Geten creates a gigantic block of ice to defend the headquarters. One Hero asks Cementoss if he is alright and he says yes, and that he will help break through Geten's ice.

The situation gets worse when the team in Jaku fails to prevent Tomura Shigaraki from waking up. Tomura orders Gigantomachia to go towards him bringing the league of villains with him. The Giant bursts out from the underground sanctuary below the Gunga Mountain Villa and runs to where his master is, sweeping everything in his path. The heroes try to stop him, but they are attacked by Geten, who's confused by the whole situation. Cementoss then attacks the distracted villain, using his Quirk to trap him in cement, while proclaiming whatever happens, the heroes must take their lives on the job.

The battle between the heroes and the Paranormal Liberation Front continues until it ends with an ambiguous result: the bulk of the Paranormal Liberation Front has been arrested, however Tomura Shigaraki had managed to escape along with a few allies, in addition to the enormous destruction generated and the countless dead between heroes and civilians.

For their part, Geten and Cementoss had managed to neutralize each other: Cementoss had ended up with several large spikes of ice imbedded in his body, but managed to trap Geten for good in cement before collapsing. Geten is arrested and Cementoss immediately sent to the hospital.