|Anime Debut||Season 1 Episode 13: Winter Days!|
|English||Amanda Celine Miller|
|Korean||Tae Yeol Jeon|
Satoshi Tainaka (
He first appears in Winter Days! when Ritsu is walking home with him from a movie they saw together. He then ventures off with a friend from school to another friend called Suzuki.
He later appeared once in a while during the series, for example when he brought his sister her student handbook in Plan!.
Satoshi seems to be a bit more mature than Ritsu, usually saying things like "Geez, be more careful next time" when he has to take care of the problems she caused. Satoshi knows Mio Akiyama because she and Ritsu have been friends for so long, but becomes shy when Ritsu brings the rest of the Light Music Club home without telling him (Ritsu supposed it as a "rebellious phase"). He is also curious about his sister's doing and eavesdrops sometimes at her door (for example, when Mio and Ritsu were practicing for their class play, Ritsu finds out that Satoshi is laughing outside her room as she practices her dialogue). He also dislikes cold weather. Although he sometimes laughs about his sister or tells her to be quiet when she practices in her room, he still respects her and asks her for permission to hang out with his friends.
Mio once stated that he is like a little version of his sister Ritsu and resembles her, especially around the eyes. Because of that, Yui Hirasawa imagined him like a "Male Ritsu". He has brown eyes and short, shaggy brown hair.