Oyajitchi- How to get him
I do know how to get him, as I have had him before, and I am currently trying to get him again.
First, a little bit of ' Rumour and Real'
Rumour: If you get Gozarutchi and have him play with the cape, he temporarily turns into oya(for only like 5 seconds). If you play with the cape constantly, he will stay oya. RUMOUR. This is not true.
Real: Mating the two old folks gets you oya. TRUE.
You may ask, "Well, it has four hearts, but they just aren't mating!". This will happen if you connect your tamas from baby to adult. Trust me, it takes FOREVER if you do it this way.
Here is the quickest way to mate your tamas:
Wait untill they are both 5 or older ( If you are looking for oya, then you wait to mate untill they are oldies. Just keep ignoring the matchmaker if this is what you want) to connect them. They should NOT know each other. When they are 5, keep connecting with them. Soon, they will both be best friends, which is 2 hearts, two faces. Connect about one more time, and they will be partners. I am not going to spoil the rest of the fun, however
If you succesfully mated your two oldies, just grow your tamagotchis up like usual.
I am glad to help! Have a fun time mating!