Maybe there is some characters we haven't yet unlocked, or it could be one of Bandai's glitches in the first wave of Tama-gos. (first wave of things are always tending to be a little glitchy or something)
~SMG~ :D
Shouldn't this be in the 'Tamagotchi Tips & Tricks' section? Anyways, great growth chart. :D I'll try to use it with my Tama-go when I can!
~SMG~ ;)