
Quick answer — Hiroki Takahashi worked on School Rumble (Theme Song Performance), Pop Team Epic Season 2 (Theme Song Performance), Hetalia World Series (Theme Song Performance) and 1 more anime.
Hiroki Takahashi worked on School Rumble (Theme Song Performance), Pop Team Epic Season 2 (Theme Song Performance), Hetalia World Series (Theme Song Performance), Hetalia Axis Powers (Theme Song Performance).