Ieji Hisashi, a salaryman who works for a securities company, has a fuzzy memory of the recent five years because of an accident at his job posting. His wife of five years, Megumi and their 4-year-old son seem to wear masks. He can neither tell their facial expressions nor their emotions. He also struggles about his love for them. On the other hand, Ieji feels an attachment to his ex-wife, whom he divorced five years ago, and their daughter. What sort of days did he have in those five years which are a blank to him? Ieji sets out on a journey to find his past self with a mysterious bunch of 10 keys that he has. He becomes aware that he was a cold, career-minded man before the accident, and the persona that is gradually revealed is beyond the imagination of his present kindhearted self.
Episode 1
Hisashi awakens after months in a coma. He returns home to his wife and child, but has no recollection of them or of the past five years.
Episode 2
After reconnecting with his old friend Yamanobe, Hisashi asks him about Megumi, but Yamanobe tells him that some things are better left forgotten.
Episode 3
Acting on a confused memory, Hisashi shows up to his ex-father-in-law’s memorial service and gets punched out by an angry relative.
Episode 4
To recall his past, Hisashi goes to the neighborhood he lived in at the time of his accident and hits it off with the guy living in his old apartment.
Episode 5
Hisashi visits his mother's house for the first time since the accident. He finds that his brother's store is struggling, and looks for a way to help.
Episode 6
Megumi suggests visiting their vacation home for some downtime, but as soon as they get there, Hisashi’s colleagues crash their family get-together.
Episode 7
Feelings of resentment consume Hisashi when his long-lost father appears. Later, he learns Megumi and Kaori were taking the same bread baking class.
Episode 8
Hisashi is taken aback by some private files on Megumi's laptop, but then he learns of his own extra-marital affair with a former colleague.
Episode 9
Megumi refuses to open up about the past when Hisashi questions her. Hisashi finds a scribbled note that may implicate his company of wrongdoing.
Episode 10
As a reassignment to Bahrain looms, Hisashi meets with Honjo, who doesn't believe Hisashi's changed. Meanwhile, Megumi visits Kaori in the hospital.
