Kazuma Rindō is a character from the anime and manga Kill Blue. He is introduced as a fifteen-year-old assassin affiliated with a dominant contract killing organization known as JARDIN. Despite his young age, he holds the prestigious and exclusive rank of "black" assassin, a status reserved for a select few high-level clients. He is often seen alongside his younger brother, Eiji Rindō, who is thirteen years old and also a black-rank assassin. Kazuma has a youthful appearance with purple eyes and shoulder-length purple hair, and his typical attire includes a hoodie and jeans.

In terms of personality, Kazuma is presented as calculating, confident, and somewhat manipulative. He is articulate and takes the initiative in conversations, especially when contrasted with his brother, who communicates only with minimal, zombie-like utterances such as "yuuuh". Kazuma displays a strategic mind and a willingness to use underhanded methods to achieve his goals. His primary and most notable ability is hypnosis, which he claims is a genuine talent that can affect any person instantly with virtually no chance of resistance. He is also proficient in combat, demonstrating skill with firearms and the use of explosive projectiles that he and his brother launch with golf-like swings.

Kazuma's motivations are tied directly to a mission involving a Mitsuoka Challenge duel. His stated objective is to win the affection of a girl named Noren for his brother Eiji, seeking fiancé status for him. To this end, he uses his hypnosis not only as a tool for combat but also as a potential means of emotional manipulation, even proposing to hypnotize another character, Chisato, to make her fall in love with his ally, Tenma. His role in the story is that of an antagonist, specifically a rival who confronts the protagonist, Juzo Ogami. Kazuma and his brother engage Juzo and Tenma in a chaotic battle, where Kazuma's strategic mind and hypnosis pose a significant threat. He is observant, quickly deducing that Juzo might share a similar line of work, and he acts decisively to prevent Juzo from retrieving his weapon by shooting down a supply drone.

His key relationship is with his brother, Eiji, for whom he acts as a protector and spokesperson. He is driven to secure a future for Eiji, despite his brother's limited expressiveness. Kazuma's primary dynamic with Juzo is one of conflict, as Juzo harbors strong, fatherly protective feelings for Noren and is vehemently opposed to Kazuma's plan to use hypnosis to secure her love for his brother. Kazuma's development within the story is limited in early appearances, where he serves as a formidable obstacle. He demonstrates a belief that love can be manufactured through his powers, which puts him in direct opposition to characters like Tenma, who believe in fair competition and genuine feelings. His abilities are shown to be both powerful and dangerous, forcing his opponents to think creatively to counter his hypnosis and tactical attacks. While he shows a cold, almost clinical approach to his assassination work and the use of his hypnosis, his dedication to his brother reveals a layer of familial loyalty that drives his actions.