Nagakura Shinpachi

Japanese name:

永倉 新八

The second unit captain of the Shinsengumi. He introduces himself to Tetsu as "Sanosuke’s keeper." Like Tetsu, he is often underestimated by his height (and young appearance — he looks like a child, but is actually in his 20s). In fact, he is extremely skilled with his sword and is a swordsman of Okita Soji's level. He is also quite the joker, especially in conjunction with Sanosuke and Heisuke.

Wikipedia