This very interesting exhibition (November 2010) by Igarashi Yoshihiko (五十嵐吉彦) at Gallery Kubota (ギャラリーくぼた) in Kyobashi, consists of a large collection of watercolor pictures - one example (from the promotional card) shown here.
I spoke briefly with the artist, Mr. Igarashi, and found out that he teaches both photography and painting. He teaches students composition and lighting with photography, and then teaches them painting skills. Most of his pictures are painted at genba (on the spot) and reflect the atmosphere of the places painted very well.
I recommend visiting this exhibition if you're in Kyobashi - it's a very nice set of watercolor pictures.
The artist's website is here:
Lyle (Hiroshi) Saxon