I just got a Pochitchi today. I took really good care of my tama from birth until the day before he changed into an adult from a Young Mametchi. Yesterday, I went out and forgot to bring my tamagotchi along, so they were in pretty bad shape when I got back to them. I spent the rest of yesterday and today taking super good care of them again, more care for my boy (who is the Pochitchi now) then my other girl, who was also a Young Mametchi, she evolved into a Tarakotchi. I spend a lot of time taking care of my boy, Rufus, cause he's so cute and lovable, even cuter now. I think that's what made the difference at the end between his becoming a Pochitchi. Hope that's helpful!