Not to brag or anything, but I figured out the fucking culprit in chapter 2, my suspicion was later confirmed in chapter 6

v--SPOILERS ALERT--v

Rule number 1 of murder mystery: It is forbidden for the culprit to be anyone not mentioned in the early part of the story
Therefore we have 6 suspects:
- The protagonist can't be the culprit cuz he's tied up
- The other two girls (Mitsuki and Haruka) can't be the culprit cuz they were being observed by mc through the camera monitors
- The other guy can't be the culprit cuz Eiji was immediately killed right after he left the room, therefore, he is not the culprit
- The victim did not commit suicide (obviously)
So, we are left with Rei who is dead (spoilers alert she's not)

In murder mysteries, there's 3 things that should be reveal to the reader at the end of the story "How dunnit", "Why dunnit" and "Who dunnit" This manga does obey the rules, but did it horribly.
For "Who dunnit", the crime was pretty easy to solve like I explain earlier

For "How dunnit"
The crime was committed by magic! No seriously, Rei is a goddamn witch. Apparently she "hypnotizes" people to do what she wants, in this case, Mitsuki. How would you feel if you spent all your time reading a murder mystery with "impossible crimes" or "perfect crimes" (that would seem like it is impossible to be committed by a human) and at the end, they told you that a witch used magic to commit the crime? They did explain in the manga but the explanation was so fucking stupid. Yes, Mitsuki was hurt about her father death. But why tf would she go out and kill innocent people (who she has pretty much zero solid evidence of them killing her father and one of them was her best friend). That, unless she's a psychopath, which was never shown or mentioned throughout the manga. With all the evidences above, I can safely say that Rei indeed used magic to commit the crime.

Also, the manga did not explain how Rei managed to hang herself on the wall playing dead while having the longest staring contest ever. Yes, she opened her eyes while she's playing dead and not blinking once. Either she's very skilled or the others are just way too stupid to notice her blinking.

One last thing, the manga did not explain how Rei survived the car accident when she was a kid WITHOUT a single scratch. She was sitting on her mom lap while her father was driving, so HOW did she survive but her mom died. And what kind of parent would kill their children just so they "can be together forever?"

For "Why dunnit"
So this girl is a TV star psychic who can hypnotize people, but people called her a liar. She got bullied at school because of that and her parent committed suicide so she decided to revenge her parent by killing people using hypnosis. Sure, this might be a good reason but it has flaws. The question here is how did she being called a liar affected her parent that lead them to suicide? It was never explained in the manga, so I just assume that the author wants us to think that her parent was tormented by the people around them (somehow). Still, that is a stupid reason for suicide. All they just have to do is move away, easy as that, their daughter is a tv star so money wouldn't be a problem. Of course, the author could have made up a reason like her parent was depressed and seeing their daughter being bullied had somehow driven them to suicide, but nope, the manga did not mention a single thing about her parent being depressed. Therefore, her parent didn't commit suicide because of her being called a liar. Therefore, Rei cannot blame her haters for her parent death.

In a nutshell, the story is horrible, the characters are stupid and unrealistic. The mystery, in my opinion, was trash, of course, that's because I've read lots of murder mysteries. So if you're new to this genre, you might still be able to enjoy reading this manga.