It's exactly how it sounds. Both your younger brother and your older brother are madly in love you to the point where they would kill others who got in there way. Be very careful not to make them mad.
When the star pupil of your Highschool takes an interest in you it causes strange feelings to emerge from your long time best friend. As time goes on, a dark, psychological rivalry blooms between the two as they both try to win your affections, soon falling head over heels for you.