Nobuteru's path into animation wasn't a straight shot. He started out working a mundane government job while just being a regular anime fan himself. Everything changed when he ran into an animator at a convention who basically told him to go for it, and he decided right then that animation was what he wanted to do.

His early work came in the form of self-published doujinshi under the pen name The Man In The High Castle—amateur stuff, but he was absorbing influences from anime and manga around him and developing his style. Once he'd built up a small reputation, he landed a part-time gig at Studio Min and DAST working on Megazone 23, which got his foot in the door.

After that, things moved fast. In 1989 he picked up character design work on the anime film Five Star Stories, and by the mid-90s he was branching into video game design. His first role designing characters for a game was Seiken Densetsu 3 in 1995, a Japan-exclusive release. But most gamers know him best for his work on Chrono Cross—he handled a ton of character designs for that one—and then continued doing similar work for other games in the Mana series afterward.