Kobayashi studied computer science at Chukyo University. After graduating, he was hired at Capcom in 1995 as a programmer on the first Resident Evil game. After working as programmer on the sequel and a planner on the first Dino Crisis game, his first producer role was on Dino Crisis 2 in 2000.
Starting with the first Sengoku Basara game (titled Devil Kings in North America) in 2005, Kobayashi worked as the producer for the video game series as well as a planning supervisor for the various anime adaptations. He was very interested in the Sengoku period and wanted to create an action game inspired by that period.