While you are there, suggest you visit Mitsukoshi department store. There is one piece there waiting for an owner. I was considering it heavily but decided to buy different watch instead. In Tokyo, there are so many choices it's hard to decide.
They seem to carry a lot of watches. Am most familiar with the ones in Yurakucho (bordering Ginza) and Shibuya...I 'think' they carry Grand Seiko but might be mistaken. Worth the visit anyway as they are crazy places to experience retail Japanese-style.