This class consists of YUBARI and SORACHI MARUs both completed in 1930 for Kyoritsu Kisen K.K. In 1938, both ships were sold to Hokkaido Tanko Kisen K.K. YUBARI MARU was requisitioned in Aug ‘41 by the IJN and registered the following month as an auxiliary collier. She was bombed and sunk by Dutch aircraft in Koepang harbor in Mar ‘42. SORACHI MARU was requisitioned by the IJA at an unknown date and served as Army transport No. 43 before being released to her owners. She was sold again in 1943 to Mitsui Senpaku K.K. She survived the war and was renamed EDOGAWA MARU in 1956. Her steam engine was changed to a diesel one in 1959 and she was scrapped in Japan in 1965.