Besides Tsunku, Masami Yone is listed as a composer in the Rhythm Heaven series infobox.
Yone is a Nintendo composer and sound designer associated with the series from its first game, Rhythm Tengoku, onward. The music credits commonly pair Tsunku, who served as composer and musical supervisor, with Yone, whose work helped shape the games’ precise rhythmic cues and melodies.
The other choices are associated with different roles or credits. Ko Takeuchi is principally known for art and graphic design, while Takafumi Masaoka is credited mainly with programming and design on later entries. Kazuyoshi Osawa is the series creator and a key director and programmer, not the additional composer named in the series infobox.
This distinction matters because Rhythm Heaven’s music is central to its gameplay: players often respond to sound cues rather than relying on visual timing indicators. Yone’s contribution is therefore part of the series’ core design identity, not merely a minor soundtrack credit.