So i believe the film starts out with an aerial shot of a city and then it cuts to a hotel room that has a few naked japanese bears/chubs in it. One by one, men start to come and each time they are greeted by a handful of guys coming over to them kissing them, licking their nipples, and sucking their cock for a few seconds. after they all enter the room, it becomes an orgy. I cant seem to find this film anywhere!
Have you tried going to hunk-ch and going to their "デブ" Fat section. You can look by release date to narrow it down a little bit.