Board Thread:Game Updates/@comment-3502824-20180103030504/@comment-33295205-20180210225437

Another way to get AR if you haven't done this quest is Tatsuta Kai/Kai Ni. All you need to do is clear 1-4 and 1-6 twice. I believe A rank is the minimum requirement but I alway shoot for S rank to be sure  If you don't see that quest, you need to clear F65 quest first.