Kenji Harima is the male protagonist, an ex-delinquent who loves Tenma. Although he does not practice any specific martial arts style, few people are able to match him in hand-to-hand combat. He has the ability to communicate with animals, and possesses a wide variety of strange and exotic pets which he named after European monarchs. He has a little brother, Shuuji, who likes Yakumo. Harima struggles often to confess to Tenma, though he knows she has absolutely no feelings for him and may even dislike him. Every time Harima finds the courage to tell Tenma his true feelings, something happens which prevents him from succeeding. Harima also must deal with situations involving his classmate Eri, unaware of the fact that she does not know whether to like or dislike him. He gets extremely jealous seeing Karasuma and Tenma together, but his attempts to put a stop to that usually end up bringing them closer. Ironically, Harima admires Nijō jō(二条丈) the mangaka, which is Karasuma's pen name. To date, Tenma has yet to hear his confession properly. He also works as a mangaka, having Yakumo as his assistant, creating another source of misunderstandings, as it took a long time for Tenma to realize that their relationship is only professional, at least by Harima's side.

Himiko is a villain affiliated with the League of Villains and part of its Vanguard Action Squad. She and the rest of her team serve as the main antagonists of the School Trip Arc. Toga is a psychotic, she loves blood and even more likes drinking the blood of her loved ones. In middle school, she had killed a boy that she had a crush on and proceeded to suck his blood out with a straw. Soon after, she disappeared and hid from the police and Pro Heros. Himiko managed to successfully evade and escape them all, until she officially joined the League of Villains. (Source: Boku no Hero Academia Wikia)