
Quick answer — Aya Endou worked on Sekirei: Pure Engagement (Theme Song Performance), Sekirei (Theme Song Performance), Ikki Tousen: Xtreme Xecutor (Theme Song Performance).
Aya Endou worked on Sekirei: Pure Engagement (Theme Song Performance), Sekirei (Theme Song Performance), Ikki Tousen: Xtreme Xecutor (Theme Song Performance).