The story of what happened to Miko-chan’s owner is fictional, but inspired by real events. The Great East Japan earthquake struck on Friday March 11, 2011 at 2.46pm local time with a magnitude of 9.0. It was the most powerful earthquake to affect Japan and the fourth largest since modern record keeping began. The epicentre was on the seabed approximately 70km off the eastern coast of the main island of Japan and caused tsunami waves reaching heights of 40.5 metres (133ft), some of which reached as far as 10km inland. The tsunami caused the meltdown of three nuclear reactors at the Fukushima Daichi Nuclear Power Plant and the nuclear complex remains an issue to this day. As of 2015, 15,984 deaths were confirmed, with around 2500 still missing and over 200,000 people relocated.
Many schools in the town of Ishinomaki, Miyagi prefecture were completely destroyed, with tsunamis reaching 10 metres in height sweeping almost 5km (3 miles) inland from the coast. The Okawa Elementary School in Ishinomaki, which is 4km inland lost 74 of 108 students and 10 of 13 staff, as they evacuated too late and were crossing a bridge over a river near the school when the tsunami reached them at 3.36pm. The tragedy has been the subject of court proceedings by families who blame the school for not evacuating when the earthquake information was received – other towns similarly affected lost no students because they had emergency procedures in place. The school has been preserved by the city as a memorial, and as a site for disaster education.
(information gathered from Japan Today, The Japan Times and Wikipedia)