[Sister and above ... Always friends ... Less than lover] To a hikikomori brother For 10 years, a strange love relationship that can not be said to anyone. "I don't feel uncomfortable ... Because Onii is my hero." My sister tries to comfort her by seeing her dark appearance. One day, she happened to see Ji-Po in the morning, and she was forced to say, "Hey, squeeze with your hands," and she couldn't refuse. From there, her request escalated and crossed the line ... The dirty room became a secret base for the two of them ...