The Aquarius AQ range
The individual AQ guitars were designated AQ-405, AQ-401, AQ-305 and AQ-301 (virtually repeating the range numbering of the AS range), AQ-605, AQ-555 and AQ-505 - as illustrated left to right in the picture.
Bodies were again either ash or alder, necks were again bolt-on maple, and fingerboards were maple or rosewood.
The AQ-605 (the leftmost of the 3 guitars pictured) used Schaller pickups, the others used Kawai branded humbuckers.
The AQ-301 and AQ-305 were both single pickup models, so obviously didn't need a selector switch - the others used a 3-position selector. The AQ-405 and AQ-401 added a push/pull on the tone pot to split the coils.
The 3-pickup AQ-555 added a mini-toggle for each pickup to switch between humbucking, single-coil and "off" modes.
Note that model designations varied, either by territory or over time. Thus the AQ-555 is also referred to as the AQ-500, the AQ-605 as the AQ-600, etc.
As well as the bass variant, Kawai also produced an AQ-1200 - a 12-string version with twin humbuckers. One of these sold recently (summer 2009) on eBay, and the seller kindly donated some photos of his guitar before it sold. Unfortunately, I wasn't the buyer!
Photos of Chris' 12 string Kawai Aquarius can be found in the owner's gallery.