The idea for this story came to Shinkai after he visited Yuriage, Natori, Miyagi Prefecture in July 2011, after the Great East Japan Earthquake occurred. He said, "This could have been my town." He said that he wanted to make a movie in which the positions of the people in Yuriage would be swapped with the viewers. The sketches that Shinkai drew during this visit have been shown in exhibitions.[15]
In Makoto Shinkai's proposal sent to Toho on September 14, 2014, the film was originally titled Yume to Shiriseba (夢と知りせば, If I Knew It Was a Dream), derived from a passage in a waka poem attributed to Ono no Komachi.[16] Its title was later changed to Kimi no Musubime (きみの結びめ, Your Connection) and Kimi wa Kono Sekai no Hanbun (きみはこの世界のはんぶん, You Are Half of This World) before becoming Kimi no Na Wa.[17] On December 31, 2014, Shinkai announced that he had been spending his days writing storyboard for this film.[18]
Inspiration for the story came from works including Shūzō Oshimi's Inside Mari, Rumiko Takahashi's Ranma ½, the Heian period novel Torikaebaya Monogatari, and Greg Egan's short story The Safe-Deposit Box.[19] Shinkai also cited Interstellar (2014) by Christopher Nolan as an influence.[20]
While the town of Itomori, one of the film's settings, is fictional, the film drew inspirations from real-life locations that provided a backdrop for the town. Such locations include the city of Hida in Gifu Prefecture and its library, Hida City Library.[21]
