Sagaru Yamazaki is a fictional character from the anime and manga series Gintama. He is a serious but somewhat unlucky member of the Shinsengumi, often serving as an undercover investigator and intelligence operative. Yamazaki is known for his quiet demeanor, deadpan reactions, and frequent misfortune, especially when paired with absurd situations or the eccentric members of the cast. He plays a supporting role in the series, contributing to both comedic moments and occasional action scenes while representing the more grounded side of the Shinsengumi.