Banban told you that he got stuck in a room that needs blue keycard. After you unlocking the room that needs blue keycard, you found a note but doesn't see Banban in there. You got confused but decided to read the note.

the note written: 'If you read this fast enough, you might be able to escape, but I'm going to hit you very, very hard :)'

Before you are able to finish reading it, Banban strikes you in the back of your head.

"Three birds with one stone! I get all of your keycards, I get the perfect specimen, and I don't have to deal with that thing down there! And it's all THANKS to you! Oh come on. I didn't hit you that hard. Or maybe I did. Either way, it's best you take a nap while I prepare for our little surgery.”

Then, you starts to feel dizzy, suddenly your vision goes blurry until you passed out. You could hear there’s a little giggle coming out of Banban. Banban then takes the unconscious body of yours to the Medical Sector where he presumably performs surgery on you. He then stitches you back up and dumps your body in the Storage Room of the Medical Sector.