Specific Tama Characters

Hiya everyone! Okay, with three different tamagotchis, three different times, I got the Mask Tama each time. He's getting a little boring. (Please excuse my Tama names, I haven't memorized the real names, so I call them by descriptions) Each time I have also gotten the Strawberry Tama too. I guess it shows a pattern of how well I take care of my tamagotchis. Anyways, could any of you PLEASE help me on how to get the Baby Mimitchi, Onion Tama, or the Fireball Tama? I'm just so bored with getting the Mask Tama each time -- I want to see some new faces! Also, if anyone is really goos with raising tamagotchis, could you possible tell me how to get Hanatchi? He has gotta be my favorite Tama chartacter. Thanks to anyone who can halp me. ^_^