If you've seen the pictures already, you'll have noticed that today's watch is a ladies watch (the wrist shot is just for a comparison of scale).
The watch is by Casio and is the model LE-51G. It uses a 451 module and shows a 4 digit display of time. It can display date and seconds too, but as both buttons are inset, you need a pen to press them.
With regards to the model, on the face it states 'Heart & Tech' just below the Casio name. It also has a small logo with a crown in the middle, and the date 1957 around the too. Under the display, there is a ribbon design with the word 'Message' printed on it.
The 1957 dare corresponds to the date which Casio Computer Co. Ltd was established. The Heart & Tech part is a bit of a mystery though, as there is nothing linked to Casio where it is quoted (although it is a fitting tag line for Casio). The Message text reads more like you can choose a message to be printed, as the watch has no databank functions. The module also doesn't appear in the Casio archives.