Shuichi Kushimori is a 17 year old high school student who lives happily with his mother and stepsister. One day, without warning, his estranged stepfather returns home from a long absence. He quickly falls into a circle of drinking and starts abusing his ex-wife and daughter.When he begins to behave towards Shuichi`s stepsister, Shuichi is compelled to take matters into his own hands.