The Gasuden Koken-ki (full name was Koku Kenkyujo Chokyori-ki. Koku=aviation, Kenkyujyo=research institute, Chokyori=long range, ki=short for hikoki=aircraft) was a long-range research aircraft of the 1930s. It was built by Gasuden (Tokyo Gasu Denki Kogyo - Tokyo Gas Electric Engineering Co., Ltd.), setting a closed circuit world record of 11,651 km (7,240 mi) in March 1938.
For basic info on the history and development of the plane please check Wikipedia.
Below are five photos from a vintage May 1937 publication showing the plane under construction at the Gasuden factory in Omori, Tokyo.