That's the 'Fairlady RS20-II', based on an SP311 Nissan 'Fairlady 1600' roadster chassis
Designed, built and driven by Mr Masao NAKAMURA in conjunction with Onda Jidosha ( Onda Motors ) of Yashio City, Saitama prefecture, Japan ( just north of Tokyo ).
The aluminium body was built by Onda Jidosha over a "semi space frame" that was attached to the original Fairlady chassis, and featured gullwing doors and the severe Kamm-inspired rear end treatment. The U20 OHC engine from the SR311 Fairlady was used rather than the R16 engine that originally came with the SP311 chassis. Contemporary reports give the weight of the car as 766kg.