It seems that Kusaka-san's Vivalo brand has been relaunched in Japan. No traces of Keirin track bikes on the site at the moment though, just traditional steel road bikes instead.
As my Japanese skills are bit rusty for the moment Google Translate tells us, somewhat cryptically:
"VIVALO lineup was only ever full order frames.This time, experience the handmade chromoly frame more peopleIf you think please, let me hang the frame in addition to the lineupSubmitted.
Even if the frame hanging, size 8 size and color from 3 colorsYou can choose. In addition, Comfort Space, Mr. EAST RIVER CYCLESHutte 8to8's three stores, the original color of each shopAnd let me also available. So, you can choose from six colors.
All geometries have been referring to the load frame produced so farI was allowed to DRESSCODE designed from scratch.Please come and look here for the first time the real chromoly frame? ! !"
For more info: http://www.vivalo.jp/