The Kanto region of Japan reported that 11.8% of the viewers tuned in on average for the fight. When you consider Kanto's population is more than 40 million and accounts for about 1/3 of the entire Japanese population it's fair to say we are talking about millions tuning in to see the fight.
Whilst the exact numbers for the all of Japan haven't been released the fight does show partially what appeal Yamanaka has in Japan and also the effect of what boxing can do on free-to-air TV where, lets be honest, boxing has the potential to draw huge audiences if done properly, as it was yesterday. It's also worth remembering that the fight was a stand alone televised bout on NTV, the thing is it was a good one and good bouts do sell, as doe exciting fighters with KO power.
If you've not seen the bout yet we do have a video of it up here, trust us it's well worth a watch.