Ichika (Renka Iwamoto) hopes that a broken family can become one again.She talks to her father Reitaro (Takezai Terunosuke), whom she has never spoken to before, and cooperates with her classmate Hikaru (Tanaka Koki) to uncover the mystery of her family.However, with Ichika's actions, her mother Kazumi (Moemi Katayama) loses control more and more.

At night, Ichika and Hikaru were talking on the school roof.Guang advocated continuing to actively promote the solution of “Photo Mystery”. Ichika remained uneasy and silent, confiding his contradictory inner world to Guang.She dreams that her family can live in harmony as before, so she is determined to solve the mystery of her family.However, as she gets closer to the answer to the mystery, the family seems to be falling apart more and more.

“It is really difficult to have a complete family...”Facing Ichika's crying, Hikari hugged Ichika calmly and encouraged her: “There is nothing we cannot know.”

Encouraged by Hikaru, Ichika is once again determined to solve the family mystery and sneaks into Kazumi's room.There, sleeping was a “family darkness” that she could not imagine...