Daihatsu is bringing two Kopen concepts to the upcoming Tokyo show: the Kopen RMZ and Kopen XMZ. Clearly a salute to (or a possible revival of?) the Daihatsu Copen kei roadster, the Kopen concepts feature a 660 cc three-cylinder engine and a CVT with shift paddles.

The XMZ is differentiated from the RMZ by black plastic mouldings over the bumpers, sills and wheel arches that lend a rugged look – they even extend up into the bonnet and rear deck. The XMZ has a sort-of hexagonal grille; the RMZ’s is trapezoidal.

Both are 3,395 mm long, 1,475 mm wide and 1,275 mm tall. They actually bear a striking resemblance to the D-X and D-R concepts shown at IIMS 2012 – albeit with more road legal-looking wheels, lamps and bumpers this time. Reports say we can expect to see production versions of the Daihatsu Kopen next year.

So there’s this, and then there’s the Honda S660 concept roadster, which is also on the Tokyo guest list. That one previews a future Beat, while obviously paying tribute to the little S500, S600 and S800 chain-drive sports cars of the 1960s. Is the kei roadster seriously making a comeback?