This reminds me of Boogiepop Phantom meets Another meets Death Note.
I'm not going to dive into the episode, but the characters themselves and what I think about them.
Kobayashi-
There is more to this person than meets the eye. What that is I don't know. However, the key thing to remember is that this person is beyond board with their current life. The MC read books, detective games, etc, but wasn't satisfied. Now that this crime as occurred and the MC is accused, life is exciting again.
I won't address the sex of the MC because I am having a questionable feeling about it. I think the mysterious appearance of the MC looking very female is key to the story.
Kagami-
Nothing much to say about him yet.
Hashiba-
This punckass b!tch motherfludpucker............Someone take his man card away and get him to a hospital to get the stick surgically removed from his ass so he can shit diamonds. Man alive! Never have I hated a character so fast. Maybe he's the real girl.
But I digress.
His overprotectiveness of his "best friend" gives me all sorts of bad vibes. This makes me believe that he is the killer or the mastermind behind it all. His overly obsessive nature to want to protect Kobayashi, to the point of trying to be with him as much as possible, makes me wonder if this is a mental instability that is going unnoticed.
Maybe Hashiba noticed that Kobayashi was bored with his life and, after a long time of planning, came up with the master plan to get Kobayashi to be the star in the murder mystery. Give his best friend the best experience of his life. However, I also think that the teacher, not a mass murderer, was killed and framed because he found out Kobayashi was actually a girl. Still to early to tell, but I think it's one of the two or a mix of those two theories.
Akechi-
This young, bad ass Sherlock Holmes wannabe probably has it all figured out or is missing some piece to the puzzle. He takes an interest in Kobayashi cause he probably realizes that Kobayashi is actually a girl and wants to know why he's hiding that fact, that punk bitch.....I mean Hashiba is overly protective and may have something to do with this, or that having Kobayashi help will prove to be fun. What that pain that he tries to hide with medication is all about, I don't know. I think it's just a side story to give the detective some depth. Could his fate turn into Death Note and he meet his demise near the end? Who knows.