Who is the person who keeps texting?

Cheer up SMS is a Korean drama Cheerup sent by glasses man. Du Haiyi, the heroine, received the death message because the glasses man retaliated against her. As a very energetic girl, Du Haiyi is very popular in cheerleading. Glasses man was jealous of Du Haiyi's popularity in cheerleading, so he thought of sending him threatening text messages. Glasses man wanted to have a chance to appear on the stage, so he sent a death message, hoping that the hostess could step down.