Quick answer — Kengo Saitou worked on Little Witch Academia: The Enchanted Parade (Key Animation), Sekai Ichi Hatsukoi - The World's Greatest First Love: The Case of Takafumi Yokozawa (Key Animation), You're Being Summoned, Azazel Z (Key Animation) and 6 more anime.
Kengo Saitou worked on Little Witch Academia: The Enchanted Parade (Key Animation), Sekai Ichi Hatsukoi - The World's Greatest First Love: The Case of Takafumi Yokozawa (Key Animation), You're Being Summoned, Azazel Z (Key Animation), Kiznaiver (Animation Director), Sorairo Utility (TV) (Director), Hetalia: The Beautiful World (Key Animation), Higurashi no Naku Koro ni Kaku: Outbreak (Key Animation), Anime AzurLane: Slow Ahead! (Chief Animation Director) and 1 more.