Hi I can say that with my Tama I started about two weeks ago and now my 2nd generation adult changed to a Mimitchi today. My first gen went: shiropuchitchi, hitodetchi, ufotchi then mametchi( I took good care to watch and make sure she never had more than one heart gone at any one time, discipline 100%-all training bars by day 2 and never let her go too long before cleaning her up-checked on her at least every 10-15 minutes thru day) She joined with a furawatchi from the matchmaker and had a puchitchi, kuribotchi, ichigotchi and then a Mametchi( I followed the same kind of discipline and care but once while he was connecting with another Tama his happiness hearts went to zero before I noticed) I also played alot of games in between feeding snacks and only played jump( cuz I'm really good at it....tried to lose games too often) Hope this will help but not sure if it really matters how good care you take cuz I know someone who let Tama call for discipline and did nothing and fed alot of snacks and didn't play many games get a young mimitchi......
Tamatansy