In 2005, Shinsatsushitsu (Consultation Room), his graduation project at Tokyo Zokei University, won the Gold Prize for the Campus Genius Award, as well as Best Picture for BACA-JA. Oyama has been formally invited to international film festivals such as the Directors' Fortnight of the Cannes International Film Festival. In 2008 he made HAND SOAP for Aichi Arts Center which won him many awards including the Grand Prix for the Holland Animation Film Festival and the Special Prize for the International Animation Festival Hiroshima. In the live motion movies Watashi wa neko sutoka (I'm a cat stalker, 2008) and Gegege no nyobo (Gegege's wife, 2010) Oyama was in charge of making the animation clips. He is now a member of CALF, which he founded with his partners, making Hokago (After School) while producing, distributing, and selling animation works.