To get mametchi you have to take almost perect care of it i don't think there is any specific gender that the tamagotchi has to be. If it does have to be a specific gender i think it is a boy. Don't let it's hearts drop below one. And keep it at the lowest possible weight. I'm not sure if this affects it but try to feed it it's favorite food. If you do this you will get a mametchi.
