****CONTAINS SPOILERS****
Wolf Tails is more Light Novel than game.
Most choices just alter how scene plays out but not the game so can pick
your preference or whatever seems funnier. No harem ending. Here are the 3 game
changing choices:

Important Choice 1: Girls have gone out to return home. Do nothing or go after
them?
  They'll be fine. - Bad Ending 1
  I'd better go find them. - Story continues.

Important Choice 2: Girls have a fight. Who do you comfort?
  Comfort Mirari. - Mirari Route
  Follow Fuyu - Fuyu Route

Important Choice 3: Injured clanwoman updates home situation. Watch them leave
or call out?
  Let Mirari go. - Bad Ending 2
Tell the girls to wait. - Good ending with whoever comforted in Important
Choice 2.