
Quick answer — Takumi Yanai worked on Gate 2 (Original Story), Gate (Original Story), GATE 2: Jieitai Kano Umi nite, Kaku Tatakaeri (Original Story).
Takumi Yanai worked on Gate 2 (Original Story), Gate (Original Story), GATE 2: Jieitai Kano Umi nite, Kaku Tatakaeri (Original Story).