Hi! I am trying to find an anime for a friend and this is the best place I can ask because the people on this site are really helpful.
He said he watched this anime in 2011 or 2012 (though it could be older than that) and it is about a college student who becomes immortal because he saved someone (?) and a god "blessed" him. The series ends with the person being utterly alone as he is the only person left alive. He does have a family in the course of the series as well, though they are not immortal. I would appreciate if anyone had any clues, I am also going to be posting this on the anime subreddit!