Kimi no Na wa. Another Side:Earthbound

Kimi no Na wa. Another Side:Earthbound (君の名は. Another Side：Earthbound) is a novel written by Makoto Shinkai and Arata Kanou with illustrations by Masayoshi Tanaka and Hiyori Asakawa which is served as a side-story to the Kimi no Na wa. film. It was published on August 1, 2016, in Japan under Kadokawa, and November 21, 2017, in English under Yen Press. The novel also has a manga adaption under the same name.

Summary
During the events of Kimi no Na wa., Mitsuha and Taki's miraculous encounter forever changed their lives and the fates of everyone in the tiny mountain village of Itomori. But their earth-shattering ordeal represents just one chapter in Itomori's history, and Mitsuha's experience form only a single thread in the fabric of her community. Every story has as many sides as there are characters to tell it, and every life affects countless others...

In Another Side:Earthbound, the stories of Mitsuha's family, her friends, and the boy from Tokyo come together to weave a greater picture of the circumstances surrounding the comet and the forces that bind the people of Itomori together.