This is an English summary that links to Japanese press articles (which I can't read). We've seen the rumors before that we might be looking at Hisanori Takahashi, so this just confirms it. The Brewers may be about to make him an offer as well.
Kobayashi was the closer for the Japan Series Champion Marines and a teammate of the just-posted Nishioka. Kobayashi is an international FA (so no posting fee). He is 32, and it looks like he converted from SP to RP just this season. His career numbers (non-MLE) aren't too shabby.