The first time I saw one was in 2001. One of my students, Thijs,  was wearing one. He had bought it at the jeweler that's also my Casio dealer. He became one of the first G-People of G-Peopleland. I don't know when this one was released, but according to the animations in the display and the spinning G, it seems this is a sort of study model for the Baby-G series. It took me at least 2 years to find this model, so I think it is rare.