1942 Born in Saitama Prefecture, Japan
1968 Graduated from the post-graduate course in oil painting at Tama Art University in 1968, where he studied under Yoshishige Saito

In 1970, Sekine represents Japan in Venice Biannual Exhibition, one of three most important art competitions in the world. Phase of Nothingness, a marble stone perched on a stainless steel column, creates a sensation and becomes a permanent exhibit at the Louisiana Museum of Art in Denmark.
After the exhibition, Sekine stays in Italy and works where he holds several one-man shows. During that time, he is deeply impressed with the way which Italian urban environment fuses architecture and art. With the aim of promoting environmental art, which has been still relatively unpopular in Japan, he returns home and establishes Environment Art Studio. Since its establishment, he has created art works and monuments in several hundred places throughout the country.
Recent important projects include Shrine of Water and Pedestal of the Sky at the New Tokyo Metropolitan Office, Waving Scenery and Wave Cone at Tama Cemetery Ossuary Tokyo, fountain sculpture Rainbow at Hotel Shilla in South Korea, Flying Rainbow at Osaka City Air Terminal.
Since 1987, Sekine has been involved with his Phase Conception Series, which has triggered changes in the concepts of painting and thought. He has also held one-man shows throughout Japan and at the Stemfli Gallery in New York.
In 1993, he and his work Phase - Mother Earth are selected as one of the best artists and artworks in the Survey of the Best Ten Postwar Artists and Artworks, which is conducted by thirty art critics in a special issue of Gigot Shincho magazine.
In April 1993, he becomes a director of International Sculpture Center, a non-profit organization in the U.S., which globally contributes to the development of various art projects.