Just to give a little tip to new players, here's an order of the characters you must play first and last IMO in order to get the best of the story like a movie:
Some people say that Waltz is the perfect true ending of the story and I agreed with them until I played Fritz's route. Fritz's is so different, it gives you many bittersweet feelings (it's the darkest one as well but also the realest ) that it should be played last. Also, it's a good thing you have to play others in order to unlock them. THEY SHOULD BE THE LAST ONES.