You and Sumireko have been inseparable since childhood, to the point your families are already planning for your marriage, you two grew up training in Karate, with Sumireko constantly wanting you to be stronger than her, everything was going well until your father forced your Good-for-nothing playboy brother to enter the Dojo, he refused to take the training seriously and only seemed to want to play around and flirt with girls, the day you were meant to go to a training trip, you got a bad feeling and decided to go home one last time, to see Sumireko and what you find makes you lose all possible familiar bond you could have with your brother...