For the 3rd event in the 1st row: when given the chance when she first appears, try to touch her. Make sure you always let her do what she wants.  WHAT'S IMPORTANT,  is that you tell Si-won everything when given the choice. Do not lie to her. Also, like I said, make sure you go along with any choice given where you allow Mal0 to stimulate/touch you.    Eventually, Mal0 will start touching you under the desk(as YOU know), a total of three times before Si-won catches on and offers to help.  YOU already know what happens if you accept, BUT FOR THIS, DON'T ACCEPT HER OFFER. AFTER YOU DECLINE HER OFFER, YOU WILL GET AN ENDING THAT IS ALSO THE THIRD EVENT ON THE FIRST ROW. 

I can't help you with the last event because even I don't have it. I also don't have the CG you need.   Also, I have all the tracks, but I don't know the PROCESS of unlocking any of them or the one you need specifically, sorry.

Also, yeah, that ending is weird. Like, I thought we let her go?   But then the phone flashes white again and we jump to a scene where she is back?  And helping us find Si-wons sister? Who is somehow trapped within an animatronic from another one of Night Fox Work's games? Weird for sure.

I have the true end and good end, but I apparently am missing two?   There's actually multiple ways to see the same scene that is displayed in the good end.    But yeah, whatever the two endings I'm missing, I have no clue of finding.

probably