Okay, first of all, if you've never seem this anime; watch it! It's great. It's a bit confusing, but great. Especially Toma. He's my favourite character on this show, and probably made my top ten favourite characters of all time. I mean, he's just, ugh, he's amazing.

As opposed to our friend (I hope everyone knows her) Gasai Yuno from Mirai Nikki (The Future Diary), I believe that Toma can be considered the Yandere King. He's super nice and sweet to the heroine, and then shit gets weird.

Basically, he figures that she's in danger, so he convinces her to live with him and not go outside. When she doesn't listen to him, Toma puts sleeping medicine in her food. When the heroine figures that out and leaves again, he puts her in a goddamn cage (I still have no idea where he got a giant cage from in one night), and when she gets out of the cage, he goes all psycho and threatens to "break her". Sooo.... 100% Yandere? He's hot though.

~~~~Example~~~~

Heroine: Me and Ikki are going to go out tonight.

Toma: (Looks concerned) Are you sure it's safe?

Heroine: Yeah. (Starts putting on her shoes to leave)

Toma: Okay, but before you go, have some tea. (Hands Heroine a tea cup)

Heroine: No way! You'll just drug me again!

Toma: ... (Hits her over the head and knocks her out) (Puts Heroine in a cage) It's only to keep her safe...

~~~~End of Example~~~~

So, that's about it. Btw, if you don't understand the "Heroine" thing, it's because the show never tells you the main character's name. So she's just refered to as Heroine... it's annoying.