There IS another ending.... I actually couldn't get the ending you're talking about for some reason. To get the ending I got, I got all the effects and caught the bird that takes you to the wings effect again. You interact with a small boy. Then you go to the hositol and you interact with Kamitsuki's mother. You then go to sleep again and go back into the hositol. There will be a room in it's place. You have to use the sword on that person. That will give you the ending I got.
Though if there was anything I might have missed for the normal ending, please tell me. I interacted with the door, but nothing happened.