Koji Sakai is a Design Director, Architect and Interior Design Lecturer at design schools, professor and researcher.He serves as Board of the Japan Interior Design Association. He had a career-forming experience 28 years ago when he got a chance to go to Milan, Italy.
There he worked in store development projects with Piero Angelo’s Studio 63 Design Firm (ITALY) and was involved in the opening of many “Miss Sixty” Mega Stores.
 
Later Koji started the SIA(Siesta-International-Associates Architects Office) with the underlying concept of “Happiness'' and introduced the Movable Tea Ceremony Space ''Dorakuan'' and ''Tomodachi(Furniture)''. He specializes in concept work and consulting utilizing design systems gained from his overseas PROJECT experience. He lectures in professional schools and colleges and offers many themed seminars. He has planned a Design Conference in Japan and has also instituted the successful Design Conference in Beijing (China) and various places as well.
 
The company researches sustainable materials and presented a chair made from bamboo at the Milano Salone 2019, which was well received. It also conducts research on IFI and APSDA design promotion policies and trends, and conducts research on the future of design.