You need 2 figures
1 from your tama-go you got with
and the other that you bought
NOTE: you must have connected both before starting this
1.connect the figure you bought, wait till it says "Welcome"
2. un-connect it and quickly connect the one you started
3.go to the shop in the figure you bought, the screen should freeze.
4.when you enter the shop buy 1 thing as you should (NOTE2: if you have over 9999 you will loose you points,if you have more then that then you'll have to buy food from the tama-go shop with the door)
5.go back to your stats and you'll have an extra figure attached
if it doesn't work try it again, it worked for me, i had 3 figures and it says 4