When the magnitude 9.0 earthquake struck on March 11 and knocked out telephone lines across Tohoku, Twitter was flooded with messages as users tried to contact people in the disaster zone with words of both concern and encouragement.
Those words are now making their way into books as memorials to the nation's biggest postwar catastrophe.
"Pray For Japan," a printed version of the prayforjapan.jp website, was the top-selling book at Kinokuniya Bookstore in New York in May, while the paperback "Quakebook" hit bookstores in Japan in mid-June. Both are written in English and Japanese.