
Quick answer — Kei Ogura worked on Legend of the Galactic Heroes Gaiden: A Hundred Billion Stars (Theme Song Performance), Legend of the Galactic Heroes Gaiden: Spiral Labyrinth (Theme Song Performance).
Kei Ogura worked on Legend of the Galactic Heroes Gaiden: A Hundred Billion Stars (Theme Song Performance), Legend of the Galactic Heroes Gaiden: Spiral Labyrinth (Theme Song Performance).