Quick answer — Keiichi Oku worked on Ojamajo Doremi Sharp (Music), Ashita no Nadja (Music), Magical DoReMi (Music) and 5 more anime.
Keiichi Oku worked on Ojamajo Doremi Sharp (Music), Ashita no Nadja (Music), Magical DoReMi (Music), Marmalade Boy (Music), Peacemaker (Music), Digimon Data Squad (Music), Dream Eater Merry (Music), A Town Where You Live (Music).
