This car is a Datsun NL-76 from 1936. It is quite an important landmark in the history of car manufacturing and car racing in Japan since it is considered as the first Nissan racecar (along with the NL-75 built at the same time but using a different engine).
The Datsun NL-76 was based on a 1935 Datsun 14 production car and used a modified version of the Datsun Type 7 engine (side-valve, 4 cylinder, 722cc, 22hp) also used in the Datsun 14 model.