In 1979, when she was a student at Tokyo Zokei University, KIFUNE Sonoko formed a unit called IKIF with KIFUNE Tokumitsu, started production of independent animation using 8mm and 16mm film, and released experimental animation, visual installations, etc. At the end of the '80s, she got involved in production of CG animation, and in 1997 established the animation production company IKIF+, which mainly produces 3DCG. She produced the animation BUBAGA for Puchi Puchi Anime on NHK Educational Channel from 1995 to 1997. In 2006, she worked as a 3D director for TACHIGUISHI-RETSUDEN, was in charge of OP animation of Doraemon the Movie: Nobita's New Great Adventure into the Underworld in 2007 and Doraemon the Movie: Nobita and the Green Giant Legend 2008. KIFUNE serves as an executive board member for both the Japan Animation Association and the Japan Society for Animation Studies, and a professor at Tokyo Polytechnic University.