Well, usually after someone goes through there trial, they carry out the ruling immidiately. Chief and his wife were tried at the same time; they both held regrets, so they couldn't reincarnate. That's why they got to stay together. If one of them hadn't had regrets, they would have reincarnated, or they both could have.

Meifu is a purgatory were people live between Life and Death. It's not an Afterlife.