Although he always wanted to be an architect, André Osi took courses in comics by Claude Renard and François Schuiten at the Sint-Lukas in Brussels. He began his professional career doing short stories for Tintin (text by Yves Duval). He also drew several stories for Hello Bédé. He then teamed up with writer Pascal Renard and began the 'Horizon Blanc' series at Lombard.
