Born in 1962. Kosaka starts his career as an animator at Oh! Productions. After leaving the company on 1986, he has worked on many titles as the animation director and key animator for Studio Ghibli, such as Spirited Away, Grave of the Fireflies and Nausicaä of the Valley of the Wind to name a few. He has also worked on many MADHOUSE productions, such as Yawara! and Master Keaton among others. He made his directorial debut with Nasu: Summer in Andalusia which was premiered at Cannes’ Directors’ Fortnight in 2003. In 2014, Kosaka was awarded as Best Animator for Director Miyazaki’s The Wind Rises at Tokyo Anime Award Festival.