My Past is Too Shameless

In a jumble of glowing letters, eleven people appeared in a damp and dark cave......

.....Atsushi held out the orb, "I don't really like to explain things, but luckily my family was thoughtful enough to put my story along with Akutagawa's in a movie form. There is also one thing you should know. This is not our first life. Our first life is contained in this orb, and we will watch it."

What happens when eleven people are transported to a random cave and now are forced to watch their subordinates past lives? And who is this baby-faced ghoul?!