The Mitsubishi Minica was one of Japan’s earliest Kei Jidosha. It features a 2 cylinder, air cooled engine, and a conventional front engine/rear drive layout.
It also features a three box body despite being shorter overall than a British Mini. Note: leaf spring rear suspension. The Minica was basically a conventional car scaled down to Kei proportions, unlike its competition. Mazda and Subaru were rear engined. Suzuki was front wheel drive. It might seem crazy given the space constraints to build such a small car with such an inefficiently packaged layout. But Mitsubishi had their reasons. The Minica was actually the car version of their 360 truck and van:
The layout made more sense in that context as originally rear seat passengers and a trunk were not envisaged as part of the package.
The “Super Deluxe” I spotted in Naha featured an upgraded, water cooled, 23 horsepower engine.
Strangely, when Daihatsu entered the Kei market, they too settled on an FR layout for their Fellow - although they used a more modern suspension and a slightly longer wheelbase for more interior room.
The Minica badge was the longest lived in Mitsubishi’s lineup lasting until 2011.