Katsuhira Agata

Katsuhira (阿形 勝平 Agata Katsuhira) is the main protagonist of the anime and manga series Kiznaiver. He is one of the group of seven kiznaivers who attends Sugomori High in class 2-A along with hellow kiznaiverification when he experiences pain in D-1.

Appearance
Katsuhira is a tall, slim young boy with droopy, grey eyes, and he often wears an emotionless expression on his face. He had brown hair as a child, however the majority of his hair turned white in the aftermath of the Kizuna Experiment. He is left with brown patches at the back of his neck and around the top of his hair. He is usually seen wearing his school uniform, which consists of a white shirt with grey accents on the cuffs and collar, a blue tie with a black cross and black trousers. A grey line runs from the top to bottom of his shirt and his breast pocket shows a distinguishable mark. He appears to be around 176 cm.

Katsuhira used to be one of the 19 children who underwent the Kiznaiver experiment. His feelings and pain were shared over to Noriko, like all the other kids, thus the reason he can't feel any pain. It is also revealed that he used to and still gets regularly bullied.

Noriko Sonozaki
Noriko and Katsuhira were both in the Kiznaiver experiment. It is proclaimed that Katsuhira used to have feelings for Noriko when they were children, and by the end of the manga his feelings for her continue.

Chidori Takashiro
Chidori and Katsuhira have been friends for a long time, even before Katsuhira became indifferent to life. Chidori calls him "Kacchon", while Katsuhira calls her "Chidori" without any honorifics, showing that he at least feels somewhat comfortable with her. She is shown to care a great deal for him, cleaning his house with him and making him lunch, and is concerned about his bullying issues even to the point of getting upset when he said it didn't matter, and initially getting jealous when he chooses to talk to Sonozaki.

Honoka Maki
Not much is said on their relationship.

Yoshiharu Hisomu
When Hisomu is first mentioned in episode 3, Katsuhira states his empathy for Hisomu and begins to feel the need to have a connection with another person. As the Kiznaivers chase Hisomu, Katsuhira soon realises that he probably won't talk to them unless only one person like himself went to him. Katsuhira goes to meet with Hisomu, who asked if he could die for him. Later within the same scene, Katsuhira causes Hisomu to bliss out after jumping off a bridge into oncoming traffic.

Later in episode 5, it is shown that Hisomu is trying to hurt Katsuhira purposefully, after asking him to hold the firewood he was chopping or if he could sit underneath it. Hisomu also states that he is especially happy to meet Katsuhira, hinting that he has a certain interest in him.

Nico Niiyama
These two seem to have a budding friendship. In episode 4, Nico gives Katsuhira the green peas she claims to dislike. In episode 5, she protests against the idea of Katsuhira getting hurt by Hisomu. But in episode 11, Nico shows that her bond with Katsuhira has developed even further, stating that she still wants to be friends with Katsuhira and share her problems with him.

Hajime Tenga
Tenga saves Katsuhira from bullies when they first meet. He is shown to care about Katsuhira when he follows him home and decides to stay home with him, vowing to protect him. In order to prevent Tenga from jumping off a bridge later, Katsuhira jumps in his place, even though his body would still be affected from the fall. He and Chidori are the only Kiznaivers to run to his aid, while the others go to check on or prevent Yoshiharu from escaping. However, in episode 9, Tenga was seen physically beating up Katsuhira in front of the other Kiznaivers out of frustration of not being Chidori's love interest. Katsuhira holds no grudge against him and forgives him despite what Tenga put him through.

Tsuguhito Yuta
Yuta and Katsuhira don't have much of a relationship besides being friends, however he does get defensive whenever he's around Honoka.

Trivia

 * He has the nickname of "Kacchon" from Chidori.
 * Unlike the other teenage Kiznaivers, Katsuhira has been part of the Kiznaiver experiment once before.
 * It is shown during a flashback that as a child, Katsuhira was afraid of his inability to feel pain.
 * As shown in episode 1 when the Kizna system activates within him, and implied in episode 10, Katsuhira has not completely lost his ability to feel pain.
 * Katsuhiras' hair colour was originally brown, but was altered due to his Kizna connection to Sonozaki.
 * Katsuhira often forgets to eat on his own
 * Katsuhira used to have a friend called Yuki.