When Hizashi was born, his newborn cries damaged the ears of his parents and the doctor who delivered him. During his adolescent years, Hizashi attended U.A. High with Shota Aizawa. While picking their hero names, Shota was unable to decide so Hizashi chose the name "Eraser Head" for him.
Present Mic first appears at U.A. High to introduce and explain the rules of the Entrance Exam to the candidates. He surprises the students when he returns to announce the practical exam's start and end.
Following the practical exam, Ochaco Uraraka tries to negotiate with him about transferring her exam points to Izuku Midoriya, who saved her life during the practical. Hizashi explains to her that Izuku doesn't need her points because he scored more than enough rescue points to pass himself.
Once the media finds out All Might is teaching at U.A., they storm the school looking for a quote from the number one hero. They somehow bypass the school's defenses and get on the property, prompting the alarms to sound. Hizashi and Shota both try to get the media off the property but they refuse to leave. Hizashi suggests they beat them up for trespassing, but Shota warns him to stand down and wait for the police to arrive.
Present Mic arrives at the U.S.J. with the other faculty members after Tenya Iida calls them to help save Class 1-A from the assault by the League of Villains. He uses his Quirk to subdue several of the villains and rescues Fumikage Tokoyami and Koji Koda.
Present Mic acts as the main commentator and announcer for the U.A. Sports Festival. He manages to talk Shota into commentating alongside him. During the opening ceremony for the festival, Present Mic announces every class that's taking part one by one. After Midnight introduces herself as the chief referee, the Obstacle Race is announced to be the first event. Midnight explains the rules and the event begins as Present Mic gives a play by play to the audience. Hizashi reveals the first Obstacle will be a blockade of villain bots he nicknames the "Robo Inferno". After Shoto Todoroki freezes a gigantic villain bot on his own, Present Mic commends him and reveals to the audience that he was a student let in on recommendations.
Present Mic explains the second obstacle is "The Fall" once the students reach it; if they fall, they're out. He mentions that it can be difficult to become a popular hero without a flashy Quirk to tease Shota. He also comments on how easily Shoto is getting ahead and that Tenya looks foolish crossing the fall. Once Shoto reaches the third obstacle, the "Minefield", Present Mic explains that it is the final obstacle and the mines aren't that powerful.
Present Mic continues giving a play by play of the race, including an excited take on Izuku's sudden pursuit of first place. He notices Shoto and Katsuki stop fighting to pursue Izuku and comments on how Shota's students are amazing. When Shota credits them for their own will to succeed, Present Mic teases him by calling him a terrible instructor. To conclude the event, Present Mic announces Izuku Midoriya as the champion and asks the crowd to cheer for all the competitors as they prepare the results.
Just as the Cavalry Battle is about to begin, Hizashi wakes up Shota in preparation for the battle royale. At the beginning, Present Mic comments on Team Mineta's clever use of Mezo's body to cover both Mineta and Tsuyu. He's excited to see Katsuki attack Team Midoriya in mid-air, but questions if leaving his team is even allowed in the event. When he decides to take a look at the rankings seven minutes into the event, Present Mic is surprised to see Class 1-A isn't doing well. He announces the halfway point of the game and ponders what will transpire next. 
When Team Todoroki freezes the other teams, Present Mic is impressed with Shota's comments on Shoto's strategy. With only a minute left in the battle, Present Mic comments that Team Midoriya has miraculously kept away from Team Todoroki for the latter half of the games. He's also taken by surprise when Tenya uses his Recipro Burst technique to steal Team Midoriya's points in an instant. Present Mic comments on all of the shake-ups within the final minute, including Katsuki's merciless assault on Team Monoma. He announces the end of the second round and all four of the qualifying teams. Afterwards, he asks Shota to grab lunch with him, but he refuses so he can take a nap.
Prior to the final round, Present Mic announces that those who didn't make it can enjoy the cheerleaders and recreational games. He and Shota are both surprised to see the girls of Class 1-A are dressed like cheerleaders as well. He also explains that the finals will be a one-on-one fighting competition. When Nirengeki and Mashirao drop out of the finals, Hizashi calls it a strange turn of events. Present Mic announces the beginning of the finals and introduces the first match between Izuku and Hitoshi Shinso.
At the start of their bout, Present Mic comments on how Hitoshi immobilizes Izuku using their Quirk. He's surprised to see how Izuku listens when Hitoshi commands him to walk out of bounds, and even more shocked when Izuku breaks his mind control. When Izuku throws Hitoshi out of bounds and wins the match, Present Mic says the match was kind of boring but still asks the audience to applaud both participants. He announces the next match and introduces both Hanta Sero and Shoto. He commends Hanta for his strong start but is silent and staring with awe after Shoto completely freezes Hanta along with half of the stadium.
The battles resume after all the ice is removed and Present Mic introduces the next two competitors: Ibara Shiozaki and Denki Kaminari. He introduces Ibara as an assassin, but she takes exception to this and questions why he did so. Present Mic apologizes and is annoyed when Ibara starts monologuing over her own humbleness. She defeats Denki rather quickly, prompting Present Mic to comment that it was over in an instant. He continues on to the next match between Tenya Iida and Mei Hatsume, but is dismayed when Mei turns the match into a commercial for her gadgets. He commentates during Mina's match with Yuga, Fumikage's battle with Momo and Eijiro's fight with Tetsutetsu. He mentions that Eijiro and Tetsutetsu's Quirks are redundant and even gives them the same introduction for their match. They fight to a draw, and while they recover Present Mic announces the last match between Katsuki Bakugo and Ochaco Uraraka.
During the final match of the first round, Present Mic makes it evident he's rooting for Ochaco. He becomes concerned when Katsuki barrages her with explosions and agrees with the crowd when they start booing him for it. However, Shota takes it upon himself to hit Present Mic and reprimand the crowd for their negativity. Hizashi is surprised when Ochaco reveals her strategy and drops floating debris from the sky. He's equally shocked when Katsuki blows it away with a super explosion. When the match ends, Present Mic calls the outcome depressing and announces that there will be a break between rounds. Before the second round's first match, Present Mic comments on the huge anticipation for the epic battle between frontrunners Izuku and Shoto.
Present Mic announces their match closely, commentating on Izuku's counters against Shoto's ice. When Shoto unleashes his flames and Endeavor yells across the arena, Hizashi hesitantly comments about how much of a good father he is. The match concludes with a gigantic explosion that Present Mic questions. Shota explains that the arena's air had been cooled then rapidly heated, prompting Hizashi to realize that is what caused the explosion.
Hizashi continues to announce the rest of the second and third rounds leading up to the final matchup between Shoto and Katsuki. Shoto opens the match with another giant ice blast and questions whether the match is already over. However, Katsuki tunnels his way out of the ice and surprises Hizashi and the viewing crowd. He commends Shoto's use of an ice wave and mentions that it looks like fun. Come the battles climax, Present Mic comments on Katsuki's Howitzer Impact technique and that Shoto refused to use the fire blast he used to beat Izuku. Afterwards, Present Mic announces the conclusion of the U.A. Sports Festival.
In the faculty room, Hizashi and Shota are both annoyed by All Might's obnoxious ring tone.
Present Mic attends a meeting with his fellow faculty members to discuss changing the final exams. He questions whether having the students fight teachers in pairs is a good idea because it may be difficult to grade them if they are easily defeated. He and the other teachers meet with the students prior to the practical exam so Principal Nezu can explain the change. He comments that it differs from combat training because the students will be up against superior fighters. Kyoka responds with confusion, claiming that Present Mic is just an announcer. This irritates him and he yells for Kyoka to have some respect. Present Mic is placed against Kyoka Jiro and Koji Koda to drown out their sound related Quirks.
Present Mic begins their battle guarding the escape gate and uses his loud Quirk to blast the entire forested area with his voice. As he waits for them to draw closer to the escape gate, Present Mic continues to yell and flood the forest with his voice. Kyoka manages to counter one of his shouts with her own Quirk, but Hizashi is unimpressed with her power.
After yelling for them to come out for a few more moments, Present Mic notices bugs coming from underground where sound doesn't travel well. He is paralyzed with fear and allows the bugs to crawl up his leg, causing him to faint and allow Team Kyoka and Koji to pass through the escape gate.
Present Mic is later seen among other U.A. teachers in an emergency meeting regarding the villain attack at the training camp and the capture of Katsuki Bakugo. Present Mic pointed out how the time of peace had made them soft and was the one to bring up the idea of a traitor in U.A. He desired to find the identity of the traitor, only for his theory to be dismissed by Midnight and Snipe.
Present Mic and Eraser Head's substitute All Might were assigned to monitoring the Second Provisional Hero License Training Exam. Present Mic tries to lighten up the mood with his commentating and All Might remarks that this is Present Mic's way of looking out for them to which Endeavor does not respond.