Born February 6th, 32 years old, 169cm, 58kg. One of the few people in Gintama with a normal mindset and common sense. Within the Shinsengumi, he is a direct subordinate of Vice-Commander Hijikata, handling intelligence, infiltration, and detective work under Hijikata's orders. He is a klutz and has a loose tongue, often failing missions because he spills secrets easily when pressured or threatened. Nevertheless, he is evaluated as the best investigator in the Shinsengumi; even if he fails, he tries again to complete the mission perfectly and eventually succeeds. Because he has such an ordinary face, he lacks presence. However, this isn't necessarily a bad thing, as his lack of presence makes him perfect for infiltration and intelligence gathering. He has played badminton since childhood and is incredibly skilled at it. Whenever he goes on an undercover investigation, he always eats anpan and milk. His swordsmanship is also excellent, to the point where he can peel an entire apple skin without stopping. He sometimes attacks using a badminton racket. In the past, he was a delinquent known as 'Mountain Yamazaki,' but after being taught a lesson by Hijikata and 1st Division Captain Okita, he joined the Shinsengumi. He is surprisingly well-endowed.