Yoshiyuki Sadamoto is mainly active as a character designer and one of the co-founders of the Gainax animation studios. The studios has produced popular anime such as 'Gunbuster', 'Nadia: The Secret fo Blue Water' and 'Neon Genesis Evangelion'. The latter was a popular manga serial by Sadamoto and published in Shounen Ace from 1995. As mangaka, Sadamoto has also made the short graphic novels 'Dirty Work', 'System of Romance' and 'Route 20' (A short manga derived from an anime project). He is additionally co-creator and character designer for video games (Chrono Cross and Project .hack).

Sadamoto also worked as an artist for the cover of Eric Clapton's album Pilgrim and as a character designer for the movie Toki Wo Kakeru Shoujo (The Girl Who Leapt Through Time).