These are all the secret characters:
1:
Question mark > Meganetchi > Ohigetchi > Nekutaitchi
(complements of the face??? Glasses > Moustache > Necktie)
2:
Question mark > Getatchi > Rakugotchi > Kabukitchi
(things you wear??? Sandal > Pillow/Mat > Mask)
3:
Question mark > Okutchi > Shiripuritchi > Ashitchi
(body anatomy??? Mouth > Bum > Foot)
(Note, Binary found this out, just I chnaged it round my way, but all this info is from binary).
I have had them all except for Ashitchi and Kabukitchi, which I am just about to get.
I have hatched them all on my entamas.