Building rooftop roller coaster being built in downtown Tokyo

Picture 10-3 "During our stay in Tokyo we climbed the 234m high Mori Tower on Roppongi Hills. From this spectacular view I suddenly noticed a department store ('Don Quixote') was having a rollercoaster built on their rooftop!

I did some googling and found that it might be starting to run by end of January 2006."
Link