Nico is a manga artist in Tokyo. Her family consists of her mother and grandmother, who live in Miyagi. Their home was washed away during the earthquake, but at her grandmother's request, her mother worked hard to rebuild the house in the same place. When Nico returns to her family home for the first time in a long time, she witnesses her grandmother's strange behavior... Since she was a child, her grandmother has always looked after and doted on Nico, in place of her mother who worked outside the home.

But why is her reliable grandmother acting like this...? Her beloved grandmother is becoming like a stranger... Nico doesn't know about dementia yet, but...