This rare alarm clock was the 2nd prize in a lotto for Super Mario Kart items only available at 7-11 convenience stores in Japan.The clock you will win has never been opened.
I do not know how many were made but it was very rare and the second best price. The “A” prize was a pair of Banana slippers.
You can read more about the contest here:
Also I did not make this video but you can see an unboxing video of it here: