TV-Series
Description
Kouko Kaminaga attends Myojo Academy as Student Number 3 in 10th Year Class Black. Orphaned young, she grew up in Clover Home—a Catholic orphanage that covertly trained assassins. Bullied by peers for perceived clumsiness and poor practical skills, her sole support was mentor Irena, an explosives specialist. Kouko accidentally triggered a bomb timer prematurely during a mission, killing Irena. Designated Irena's successor, she sank into isolation and self-blame.

As Class Black's representative, Kouko exhibited academic excellence and diligence, handling roll calls, fee collections, and tutoring classmates like Haru Ichinose. Her reserved, serious demeanor concealed profound guilt over Irena's death. She abandoned prayer, believing divine aid had failed her.

Kouko specialized in explosive assassinations, deploying devices like refrigerator grenades, soda-can pipe bombs, and charm-triggered library explosives. Meticulous plans to kill Haru failed due to Tokaku Azuma's interventions. After exhausting her resources in a confrontation, Kouko surrendered peacefully, becoming Class Black's second expulsion. A red spider lily marked her vacant desk.

Post-expulsion, Kouko initially accepted her role as Irena's Clover Home successor but defected. In the anime, she shot pursuing nuns while wearing Irena's crucifix necklace, implying a campaign to eliminate the organization for freedom. The manga depicted her lying in wait with a firearm as an active assassin. An official doujinshi showed her seeking refuge with Suzu Shutō after Clover Home targeted them; they lived secluded, collaborating on a bomb collar for Suzu's assassination attempt.

Kouko has black twin-tails with curled ends, light blue eyes, and oval glasses. She wore the Class Black uniform—blue shirt, white skirt with blue trim, black tights, and ballerina shoes—sometimes accessorized with Irena's necklace. Her strengths were strategic planning and explosives expertise, evidenced by detailed facility blueprints, but she lacked physical combat and firearms proficiency. Personal details include a July 25 birthday, Kanagawa (Yokosuka) origin, chocolate preference, offal aversion, six-hour sleep average, and reading hobby.