Bro that close friend of saimai in starting chapters did the to saimai if you remeber she was saying"teacher has told you to come to him" like this man that close friend of her, she lured saimai to that trap she didnt even considered her as her close friend, I know that she would have wanted to escape from this situation as fast as , but I didnt think she would sacrifice her best friend man ,I knew from start that it is somehow connected to her close friend!!I don't rember her name because she hasn't been coming in previous chapters!!