Kozoin Ishun, also commonly referred to as Inshun Houzouin, is a supporting character from the anime Samurai Bride. She is the youngest member of a faction known as the Dark Samurai and distinguishes herself by being the only one among them who does not wield a sword; her primary weapon is a jūmonji yari, a cross-shaped spear. Her combat style relies on psychological methods rather than brute force. She is capable of casting binding spells that restrain an opponent's fighting ability and possesses an intuitive talent for predicting an enemy's next move. Beyond her supernatural skills, she can communicate with animals such as birds and perform intricate sealing techniques.

Underneath her role as a living weapon, Ishun harbors a deep internal conflict. She yearns to be recognized as a single, honorable samurai rather than a vessel for countless wrathful spirits. In a moment of intense emotional clarity, she breaks down in tears and confesses that her truest desire is simply to engage in a straightforward duel as an individual warrior, a sentiment she shares with others like Musashi Miyamoto. This struggle between her duty as a tool and her longing for personal honor defines her motivation. Her role in the story highlights the tension between forced allegiance and genuine warrior spirit. Although her direct connections with other characters are limited, her interactions with the Dark Samurai group and her unique non-sword approach set her apart. The development she undergoes, from a conflicted servant bound by spiritual constraints to someone who openly voices her wish for a fair one-on-one battle, reveals the wounded humanity beneath her formidable exterior.