Yasuchika Haninozuka (Chika for short) is Honey's younger brother,age 14. Like Honey was, before he joined the Host Club, Yasuchika is the captain of the "Karate Club." He has issues with Honey quitting the Karate Club and joining the host club. He calls Honey an alien due to the fact Honey can eat 3 cakes in less than a minute and never gains weight. Although Chika resents Honey, he still admires his older brother for his karate skills.
Yasuchika and Honey also appear to be quite similar in that Yasuchika cries very easily and loves small animals. Yasuchika will however hide these parts of his personality from everyone in order to appear stronger. This was demonstrated when Chika tried to hide the fact that he wanted to see Mori's new pet chick, Piyo-chan, despite Chika having a love of chicks (he has a secret collection of chick toys, books, etc).
Yasuchika is good friends with Mori's younger brother, Satoshi Morinozuka, as well. However, he treats Satoshi in a somewhat annoyed manner. In high school, Satoshi came up with the idea of making up their own host club to "carry on Big Brother's [Mori] and Tamaki's legacy." Yasuchika is later persuaded by Satoshi to join the club because "there will be rabbits, hamsters, lesser pandas, and of course, chicks."