Interesting anime. Definitely kept my attention. I relate it to life where people come and go, and you keep the 'treasures' in your heart.
Though at some point of the series, I kinda felt like tearing the entire arbiter premise down. Who makes it that someone should be 'judged' by putting them in a fight or flight situation and flight is 'rewarded' in the form of reincarnation while 'fight' is punished by via being sent to oblivion?