Well the young mametchi can become an adult mametchi if you raise it right, I got the adult mametchi from that, just raise it perfectly before the 4th day in which it is suppose to grow up and "evolve" into its adult stage. Full training points, don't let it drop down more than one heart and hunger, and play with it a lot, give it sandwiches which it seems to love the most and avoid the pizzas which it dislikes above all others.
Mametchi was the one char I definately wanted and that was how I got it, first time playing and I got my fav tama, not bad hm?
Anywho, the young one sleeps at 8 wakes up at about 8-10 and adult just sleeps a little later, at 9PM.
Later
Nathan T.