The 'boy' fights with his mother from morning and leaves home. On the bus to the mountain, he meets 'younger sister' and her 'older sister', who go hiking after a long time. However, the 'boy' was kicked out of the bus after being found to have paid less bus fare.

Violent father Moo-jin, whose family is everything. Mother So-yeon left because she couldn't stand the violence. Hoon, who loves both his father and mother, is forced to make a choice and leaves, but eventually remains alone and enters his world.