Is It Me, or Her?

A romance story about Endo Mamoru and Kazemaru Ichirota. They were having a good relationship they were very happy together; however, they are shounens'. They have to marry a woman in the future. This takes place in high school, Raimon High School, and one day, both of there lives became a horror. Endo's parents got a fiance for Endo, but he wanted Kazemaru.