Everything revolves around a gun that, in the change hands, raises and explode some relational situaizoni between a comely and complacent girl and her acquaintances / friends.

Asami returns home for the third anniversary of her mother's death. Her father, Shinji, said he had rented an apartment near their old house and was living in a neatly organized room. After the memorial service, Asami receives a letter from her mother's best friend, Taeko, which her mother had left behind, and learned that she and Shinji were not related by blood.