A school bell rings and excited giggles and the patter of rubber-soled shoes echo down the corridor as Shinichiro Hiratsuka, principal of Midoridai Junior High School in the city of Natori, Miyagi Prefecture, sits in his office picking over memories of the past decade.

They start on March 11, 2011, when he was stranded at his then-workplace in nearby Ishinomaki, unable to contact his wife, Naomi, or return to his home, normally a 20-minute drive away, due to the havoc caused by the earthquake and tsunami that struck earlier in the afternoon.

Four days would pass before he learned that the eldest of their three children, 12-year-old Koharu, was missing, and another five months until they found her. She was one of 74 pupils at Okawa Elementary School who perished during the 3/11 disasters.