One of the tastiest forbidden fruits has always been the Daihatsu Copen, a pint-sized fun car you can still buy in Japan. The second-generation model went on sale back in 2014 and has spawned several versions, including a fixed-roof coupe derivate, a GR Sport, and a retro-flavoured Cero. This Vision concept heading to the 2023 Japan Mobility Show later this month might be a Copen with a familiar design but it's a substantially different car.

For starters, it's way larger than the namesake production model. The regular Copen is a kei car, so it must abide by certain size restrictions. While the standard model is only 133.7 inches long and 58.1 inches wide, the Vision stretches 3,835 millimetres (151 inches) long and 1,694 mm (66.7 in) wide. The conceptual vehicle is slightly lower (1,265 mm/49.8 in vs. 1,280 mm/50.4 in) and has a much longer wheelbase of 2,413 mm (95 in) compared to the kei car's 2,230 mm (87.8-in) distance between the axles.

Daihatsu Vision Copen

The Copen has blossomed to become nearly as big as a Mazda MX-5. Much like the MX-5 – which was updated in Japan this week with an ND3 version – it adopts a rear-wheel-drive layout. As a refresher, the kei car routes power to the front wheels. Speaking of which, the Vision is presumably a lot more potent since it eschews the turbocharged 0.6-litre, three-cylinder engine in favour of a bigger 1.3-litre unit. Since displacement has more than doubled, surely the output has increased well beyond the kei car's 63 bhp and 68 lb-ft.

Rather disappointingly, the Vision Copen appears to have an automatic transmission instead of the manual gearbox offered for the standard model, which can also be had with a CVT. According to the press release, Daihatsu says the internal combustion engine has been developed to run on CN fuel, which likely refers to carbon-neutral fuel.

The design makes the Vision Copen instantly familiar even though the car is much larger now. We can't see it with the roof up for now, but Daihatsu says the vehicle has been conceived to mimic the Active Top of the first-generation model. It's an electrically retractable hardtop, and the car should still offer some practicality with the roof folded given the growth spurt. Inside, it has a digital instrument cluster, a relatively small infotainment, capacitive-touch buttons à la Porsche, and door loops.

The Copen is the last from the old guard of sporty kei cars as the Honda Beat's successor, the S660, was axed in 2022. The Suzuki Cappuccino was discontinued back in 1998. The mid-engined Autozam AZ-1 bowed out in 1994 when the Suzuki equivalent – dubbed Cara – was also dropped.