It is referred to as the ”Dime MD edition” Tuna, a very limited run of 50 watches made in 2010 especially for a japanese lifestyle magazine for an aticle/edition under the theme of ’from the board room to the beach’ or something like that. AFAIK these have no official model/reference number and were never sold through any ADs, only distributed through the magazine (but not 100% certain about the latter).