To get the memetchi family (and memetchi):
Have the first or second child a girl. Train the tamas on the second training item (the item in the middle) when it is training time. Before they evolve into adults, make sure the bonding is 80+. You should get a memetchi. Now, to get the pure memetchi family, continue training until 100% bonding and have your memetchi marry a mumutchi.