I am looking for a oneshot manga about a girl inside the train who saw a boy that was troubled because of his popularity with girls. That's why she suddenly pulled him together inside the train. They were school mates and not really acquainted but the girl know his name. Then they agreed to pretend that they are going out prevent girls from confessing to him. The girl actually likes him secretly and was cornered by the boy's fanatics... I forgot what happened after.