In junior high, Hitoshi was constantly told that due to his Quirk's nature, he was suited to becoming a villain. Although he kept his ambition to become a hero, Hitoshi became resentful of those with Quirks more accepted by society.
When a crowd blocks Class 1-A's exit, Katsuki Bakugo claims the crowd is there to scout the competition. Hitoshi walks to the front of the crowd. He confronts Katsuki directly and explains that although he desired to be in the Hero Course, he was forced to take a different path. With the U.A. Sports Festival approaching, Hitoshi and other students will have the opportunity to usurp students in the Hero Course. After explaining this, Hitoshi says that he is not there to scout, he is there to declare war.
Weeks later, Hitoshi and his General Studies Course classmates take the field for the opening ceremony. Afterwards, Hitoshi participates in the Obstacle Race, avoiding Shoto Todoroki's ice while being carried by other kids, and places twenty-seventh.
Having qualified for the Cavalry Battle, Shinso teams up with Nirengeki Shoda, Yuga Aoyama, and Mashirao Ojiro and brainwashes them as well. By the end of the Cavalry Battle, Team Shinso places third after Hitoshi uses his Quirk to brainwash Team Tetsutetsu and steal their points. Afterwards, he thanks his "teammates" for their hard work.
The final round of the festival is revealed to be a One-on-One Fighting Tournament. Hitoshi tries to confront Izuku Midoriya, his matchup for the first round, but Mashirao warns the Izuku not to respond to the Hitoshi's provocations. When their match begins, Hitoshi provokes Izuku into talking by insulting Mashirao and brainwashes him.
Now that he has taken control of Izuku with his Quirk, Hitoshi orders him to leave the ring and Izuku proceeds to do so. However, before Izuku goes out of bounds, Izuku uses One For All to break his own fingers and free himself of Hitoshi's control. Hitoshi tries to get Izuku to speak, but eventually realizes that Mashirao must have warned him before the match. Izuku tries to push Hitoshi out, but he punches Izuku twice to break his hold.
He continues to try and force a reaction out of Izuku by talking about how his Quirk puts him at a disadvantage and how Izuku is blessed to have a heroic. Then Hitoshi goes to push Izuku out of bounds, but Izuku counters and shoulder throws Hitoshi out of the ring. Having lost, Hitoshi appears to be greatly irritated. Izuku tries to console him by asking what is driving him to become a hero, but Hitoshi says it is simply what his heart longs for and leaves the ring.
Despite his loss, Hitoshi is greeted by his classmates' praises, as well as the praises of several viewing Pro Heroes. Having been encouraged, Hitoshi tells Izuku that even though he lost, he will still become a better pro than everyone in the Hero Course. When Izuku responds, Hitoshi brainwashes him temporarily and then stops to warn Izuku not to let his guard down. Hitoshi then tells Izuku not to lose and walks away.
At some point following the Sports Festival, Shota began training Hitoshi.
As all the students head toward Ground Beta for the second semester opening ceremony, Hitoshi complains that classes 1-A and 1-B are holding up the back of the line. Hanta Sero comments that Hitoshi seems a little rougher than he did before.
At the beginning of December, Class 1-A and Class 1-B gather at Ground Gamma for their first Joint Training Battle exercise. Vlad King and Shota settle down the classes and introduce Hitoshi, revealing he's a special guest participating in the exercise, and that he hopes that he can join the Hero Course.  The class enthusiastically greets Hitoshi, while commenting on his outfit, noting his mask and the Capturing Weapon he's wearing. At Shota's urging, Hitoshi introduces himself to the class. He tells everyone that his goal is to become a great hero who can help people with his Quirk,
As Shota and Vlad explain the rules of the exercise, and that Hitoshi will participate in two battles; one with Class 1-A, and one with Class 1-B. After Class 1-A and 1-B draw lots to determine their teams, Hitoshi draws his own lots. He's placed into Class 1-A's Team and Class 1-B's Team 5. As Class 1-A prepares for the first match, Hitoshi explains his Quirk to his teammates, going over the strengths and weaknesses of the Quirk. He explains that the Artificial Vocal Cords allow him to change his voice, helping against those who know his weakness.
The match begins shortly afterward, and Class 1-A's Team 1 laments they didn't get to form a proper plan. They decide that regardless, they'll have to fight to win. 
As Class 1-A moves through the battlefield. Suddenly, Jurota Shishida, carrying Kosei Tsuburaba on his back, attack them and smashes both Eijiro and Tsuyu. After a short scuffle, Hitoshi uses his Super Move: Artificial Vocal Cords: Persona Chords, to mimic Kosei's voice and brainwash Jurota. Hitoshi tries to restrain Jurota with his Capturing Weapon, but Kosei quickly traps him with Air Prison.
During the following skirmish, Tsuyu Asui managed to capture Kosei, but Jurota captures Eijiro Kirishima and Koji Koda before retreat. Hitoshi is released from the Air Prison and apologizes for his lack of battle readiness, but Tsuyu counters with her own apology as Denki Kaminari tries to cheer Hitoshi up.
The remaining trio devise a plan to defeat Class 1-B. With her mucus, Tsuyu manages to fool Jurota's sense of smell, Denki uses his Sharpshooting Gear to locate Class 1-B' team, and acts as bait, helping Tsuyu and Hitoshi get into place unnoticed.  Hitoshi gets into position within the maze of pipes, and waits for his opportunity to strike. He calls out to Ibara Shiozaki with his voice changer, mimicking Hiryu Rin's voice. Ibara responds, falling victim to Hitoshi's Brainwashing.
Jurota identifies Hitoshi's location, and eventually reaches his hiding spot. Hitoshi uses his Capturing Weapon to bring down a large pipe on Jurota's head. His plan fails to knock out Jurota, but Tsuyu throws Hiryu at him and knocks them both out, saving Hitoshi. Thanks to this, Class 1-A wins the first round. Despite the victory, Hitoshi expresses his frustration at being unable able to apply much of his training, but Shota assures him that it will take time for him to become a pro. The other teachers expresses their admiration of Hitoshi's skills.
After rounds two, three and four are finished, Hitoshi prepares for Round Five, with his teammates from Class 1-B. Hitoshi and Neito Monoma agree to take care of Izuku, while the rest of the team take care of Izuku's teammates. After the battle begins, Hitoshi hides near Neito, and spots Izuku. He uses his Artificial Vocal Cords to imitate Ochaco Uraraka's voice, startling Izuku.
Soon after, he witnesses Blackwhip's power exploding out of Izuku, and his struggles to contain it. The black tendrils begin to latch on to objects in the area, pulling Izuku through the maze of pipes to where Hitoshi's hiding. He yells for Hitoshi to run, terrifying him. He later witnesses Ochaco grabbing Izuku. She yells for Hitoshi to brainwash him, in the hope that the out of control power will subsequently stop. He removes his mask and says, "Let's fight!" to Izuku. Izuku replies by agreeing, and falls under Hitoshi's Brainwashing once again.
After the mysterious power of Izuku's comes under control, the match continues. Izuku confronts Hitoshi directly, who tries to counteract him, and then tries to flee when he realizes that he can not deal with him. However, Izuku ends up capturing him, while the rest of the team members of Class 1-B are defeated and captured by the 1-A team. Hitoshi expresses his surprise and frustration with his loss, but nonetheless smiles, musing that the Hero Course is rather impressive.
After the match, Hitoshi expresses to Shota and Vlad that he knew the exercise was meant to serve as his entrance exam for the Hero Course, also saying that he was disappointed in his performance. When Izuku thanks him for helping him, Hitoshi declines Izuku's gratitude, claiming that he he acted on his own desire to have a rematch with his old rival. Shota scolds him, telling him that it's okay that he acted selfishly, noting that Heroes can't help others if they can't find a strength to drive them forward.
Hitoshi is bewildered by all the kind words, but even more bewildered when Vlad King announces that Hitoshi will be joining the Hero Course starting from his second year.