Named in honor of Tsutomu Sakanoue (b. 1921), professor emeritus of Kyushu University whose specialties included agricultural meteorology, countermeasures against meteorological disasters, medical meteorology and rainmaking. An amateur astronomer with particular interests in atmospheric seeing, the green flash and shadow bands, he contributed to the popularization of astronomy as an advisor at several science museums. He also served as vice president and president of the Oriental Astronomical Association. Name proposed by the discoverer following a suggestion by S. Murayama, T. Sato and A. Fujii.