SPOILERS
Basically the alarms and lights go off again and MC's computer goes kind of crazy revealing that whoever is in charge of the study can see camera footage, has their survey answers, can see their pictures and chats, etc
MC then chats with "the system" but figures out who it is because they use "^^" emojis
Datu comes clean in a video to everyone, explaining that he set up the survey because he was feeling lonely too and decided to bring them all together because all of them left the answer to the last question ("what would improve your situation" i think?) blank. He explains that his parents were scientists researching a toxic fungus when the lab caught on fire. He was outside playing at the time, but his parents didn't know that and went to look for him, passing away in the process. He then went back in to look for his parents before getting saved, but got burned and getting exposed to a lot of the toxic fungus fumes in the process.
He explains that he's going to go through a risky procedure to potentially improve his health and wanted to see if he could make connections before that
Everyone in the chat is upset that he would just disappear without telling them and ask if he will open the doors so that everyone can meet up for a sleepover, which he does and its implied that everyone becomes friends
This was all from memory so it might not be 100% accurate lol if anyone notices a mistake please correct me!!