Shihai Kuroiro/Synopsis

U.A. Sports Festival Arc
Shihai first appears at the opening ceremony for the U.A. Sports Festival. He takes the field with his fellow classmates in Class 1-B. Shihai is able to qualify for the Cavalry Battle after taking thirtieth place in the Obstacle Race. For this event, Shihai teams up with classmates Neito Monoma, Sen Kaibara, and Kosei Tsuburaba.

Forest Training Camp Arc
When Class 1-B arrives at the training camp, their homeroom teacher Vlad King explains that they will be extending their Quirks and that the more they use their Quirks, the stronger they will be by breaking their limits. When Class 1-B witnesses Class 1-A's training, Itsuka asks Shota how they can observe everyone, and he explains that is the reason the Wild, Wild Pussycats are around.

Later that night, Class 1-B acts as the scaring group during the test of courage. However, the fun is interrupted when the Vanguard Action Squad of the League of Villains rampage through the forest in search of Katsuki Bakugo. It is later revealed during the aftermath that Shihai was among the 15 students that were in critical condition thanks to Mustard's Gas.

Shie Hassaikai Arc
Neito Monoma reveals that all of Class 1-B has passed the Provisional Hero License Exam, including Shihai.

Joint Training Arc
Shihai and the rest of Class 1-B arrive at the Joint Training Battle with Neito loudly claiming that the momentum is now moving to their side. Upon selecting teams, Shihai is paired up with Itsuka, Kinoko, and Manga for the Round 2.

As the second round starts, Fumikage and Shihai discuss the similarities of their Quirks, expressing their mutual understanding of the darkness and declaring a fated battle between themselves. The battle begins as Team 2-A sends Dark Shadow to ambush Team 2-B, Shihai takes advantage by hijacking the dark entity and uses it to counterattack against Fumikage. Momo tries to capture Shihai once he flees from Dark Shadow's body and fuses with the shadows of a nearby pipe. However, it is revealed that Shihai's declaration towards 1-A was all a ruse as he immediately switches to hiding within the shadows and attempts to drag Yuga Aoyama away from his team.

Despite this, Fumikage manages to save Yuga from Shihai's clutches using his newfound technique from his mentor Hawks. Momo then tells Yuga to shoot out his Navel Buffet Laser, which forces the scheming hero to escape from the shadows. Toru tries to capture him but Kinoko's interference with Momo's plan allows Shihai to blend in with some dark-colored mushrooms.

Thanks to Kinoko's plan, Shihai manages to catch Fumikage off guard by swiftly dragging Yuga towards his team's cage through the dark-colored mushrooms. He later meets up with Kinoko, in which she compliments him on his success, and suggests that they take the initiative to attack the 1-A team together, since that they have kept their locations hidden thus far. Shihai questions Kinoko's conclusion, as he notices Fumikage heading straight for them. Fumikage proceeds to attack the two with Abyssal Black Body Sabbath, which scatters both Shihai and Kinoko. Shihai attempts to find somewhere to hide, but Fumikage traps him with his cloak. Despite this, Kinoko and Itsuka's intervention allows his team to win the match.

Later on, Shihai and Fumikage are shown to have bonded with each other. Both chuunibyous express interest in Izuku's new Blackwhip technique, wondering what to name it during the aftermath of Round 5. Shihai and his classmates are present when Vlad King announces that Hitoshi Shinso will be joining the Hero Department next year. In the evening, Class 1-B visits Class 1-A's dormitories for socializing and dinner. Shihai shows a bit of jealousy when he watches Kinoko, who actually wanted "private" pictures of Hawks, engage in a conversation with Fumikage.

Endeavor Agency Arc
With the Hero Public Safety Commission's demand of all the students heroes participate in practical field training, Shihai and Kinoko are working together.

Paranormal Liberation War Arc
The months go by until it's late March. The Hero Public Safety Commission had uncovered the plans of Tomura Shigaraki and his organization, the Paranormal Liberation Front. They organize a large force of heroes to take the villain organization down. While a team of heroes raid the Jaku General Hospital, where the Nomu are created, another team does the same at Gunga Mountain Villa, the Front's main headquarters.

Shihai is a member of the Villa Backup Team along with some of his classmates and Class 1-A students. Their mission is to provide support to the heroes who raid the Gunga Mountain Villa and prevent villains from escaping.