Satoshi Morinozuka is Takashi Morinozuka (aka Mori)'s younger brother. He is captain of the junior high school Kendo Club and is also a member of the Karate Club, of which Yasuchika Haninozuka (aka Chika) is captain.
Compared to his brother Mori, Satoshi is talkative and outgoing. He is also a devoted member of the Morinozuka clan, going so far as to hit Chika with a stick when he is rude. Satoshi is friends with Chika and cares about him, as demonstrated when he quickly apologizes after making the boy cry. In contrast to Chika'sdisdain for his older brother, Honey, Satoshi actually adores Mori even though they are so different.
AppearanceSatoshi and Mori are nearly identical in appearance, with Mori being slightly taller than Satoshi.
Satoshi is first introduced with Yasuchika in chapter 29, after Honey mentions to Haruhi Fujioka during the cultural festival that both he and Mori have younger brothers. In a small part of the manga, it's shown that he likes spicy food, after the twins put hot sauce in his tea. Satoshi only appears in the manga a few times, and never in the anime.