Named in honor of Tsutomu Soejima (b. 1950), a Japanese amateur astronomer and secretary of the Saga Astronomical Society since 1989. He is a board member of the astronomical society's observatory, the Tara Observatory and the Saga City Observatory. His main interests are comet hunting and photography. Name proposed by the discoverers following a suggestion by Y. Yamada.
Discovered on 15-10-1990 in Kitami by Endate, K., Watanabe, K.