Database mirroring and service accounts

Hi,
I am trying to configure database mirroring with sql server 2012.
My principal instance and my mirror instance are on different server.
Both SQL Server service run with NT SERVICE\MSSQLSERVER.

Now when I am configuring database mirroring, which service account should I use ?
database account or server account ?

Instead of using domain account, can I :
1- create local account on my two server
2- Add these 2 logins in my 2 instances.
3- use these local account for configuring database mirroring.

regards