If you could describe our night and day series in few words, it’d definitely be sophisticated and functional. For so long, the sun and moon-clad, multi-layered beauty was a prime example of how one of our “busiest” dials to date could still be presented as an elegant time piece. But what if we refined the design by removing a few complications? Enter the new RA-AS01 Open Heart.

As a slightly slimmed down version of the open heart model that was introduced two years ago, this new model adopted bar index hour markers instead of Roman Numerals.  Its mirror-polished case are translated to the hands and dial hardware. The open heart window sits at the nine o’clock position while the day and night register is below at the six. As mentioned, the entire collection has been known for its incredible depth and attention to detail, and none of that is lost with the open heart variation. With a little help from its slightly domed sapphire crystal, a side view of the dial will showcase all of its ornate articulations, including the depth and layering between the open heart window and the movement itself.

Dimension-wise, the RA-AS01 Open Heart measures just 41.5mm wide and 13.8mm thick. It is powered by the new automatic/mechanical caliber F6L24, and fully viewable through the exhibition case back. Unlike the deployant claps seen on similar models, a strap and buckle was included to conform to its slimmed profile. The RA-AS01 will be available in two colorways: white, and mother of pearl blue, which has not been seen since the limited edition Kamasu model.