UPDATED at 11:46 AM ET - Tony Loiseleur has a first-hand report up at Sherdog:

“I initially said I wanted to fight a strong foreigner for VTJ, but when they told me who it was, my reaction was, 'Are you for real'?” chuckled Sato.

At today's "GIG TOKYO" show in Shinjuku Face, Shooto promoter Sustain revealed the addition of a major fight to the rapidly approaching Vale Tudo Japan '09 (10/30). Previously announced participant Rumina Sato (24-14-2) has found an opponent in former DREAM Featherweight Grand Prix semifinalist Joe Warren (2-1). The bout will be contested at 63kg (~139 lbs.) under "VTJ Rules," which include legal stomps and knees to the head of a downed opponent.

The forever-title-chasing "Moon Wolf" Sato has been mired in a protracted slump, having won just one of his last seven bouts dating back to 2005. After 15 years in the Shooto circuit, Sato talked openly earlier this year about his desire to test himself in the Zuffa-owned World Extreme Cagefighting. It appears he'll settle for a drop in weight and a stern test from an American rookie who'll enter this bout with a full head of steam.

Former Greco-Roman world champion Warren is just weeks removed from his first career loss, which came by way of a Bibiano Fernandes armbar in the semifinals of DREAM's 2009 Featherweight Grand Prix. Prior to the bout, underdog Warren mauled both Chase Beebe and "Kid" Yamamoto in the first two fights of his MMA career.

The full card for VTJ '09 is expected to be released shortly, so stay tuned to Bloody Elbow for more news.