Founded in Tokyo in 1946, Casio built its global reputation on precision electronic instruments before launching the G-Shock in 1983 — a watch born from a single ambition: to create a timepiece that could survive a drop from a three-storey building. Four decades later, the MR-G sits at the very top of the G-Shock hierarchy: Casio's flagship line, hand-assembled at the Premium Production Line facility in Japan, where aerospace-grade materials meet traditional Sallaz mirror-polishing techniques. The MRG-B5000BA-1DR "Ao-Zumi" takes its name and colour story from the blue-toned sumi ink used in Japanese Zen calligraphy and painting — a material long associated with calm and meditative focus.

Reference MRG-B5000BA-1DR is a 49.4 x 43.2 mm Tough Solar digital watch, 12.9 mm in thickness, built directly on the form of the original DW-5000C from 1983 but executed in materials of an entirely different order. The Ti64 titanium case and back cover carry a black diamond-like carbon coating, while the 25-component bezel top is crafted in COBARION — a cobalt-chrome alloy four times harder than pure titanium — finished with blue ion plating that gives the watch its distinctive ao-zumi character. The sapphire crystal is treated with blue vapour deposition, adding further depth to the overall colour story. The black negative LCD dial displays hours, minutes, seconds, day, date and month, with full auto LED backlight. The Tough Solar movement powers Multi-Band 6 radio-controlled time synchronisation across six global transmitters, Bluetooth smartphone link via the Casio Watches app, world time across 39 cities, 1/100-second stopwatch, countdown timer and five daily alarms — with a power reserve of approximately 22 months on a full charge in power-saving mode. Water resistance is rated to 200 metres. The watch is fitted on a DAT55G titanium bracelet — a special titanium alloy three times harder than pure titanium — with blue ion-plated band pins and a security deployant clasp.

This Casio G-Shock MR-G Ao-Zumi Limitede Edition is in near mint condition and comes as a full set.