TThis class consists of RYOYO and SOYO MARU both completed in Jan ’31 for Toyo Kisen K.K. RYOYO MARU was requisitioned by the IJA and seved as Army transport No. 488. SOYO MARU was requisitioned by the IJA and then by the IJN and was registered in the IJN in May ’39 as an auxiliary transport and rerated an auxiliary collier/oiler in Nov ‘40. Both were torpedoed and sunk in Dec ‘43 and May ’44 by American submarines.