We have revealed that the light novels Boku ga Aishita Subete no Kimi e ( To Every You I've Loved Before ) and Kimi o Aishita Hitori no Boku e ( To The Solitary Me That Loved You anime films .
Therefore, the release of both novels was simultaneous in June of this year.
Synopsis Boku ga Aishita:
The story takes place in a world where traveling to parallel worlds is a common, everyday occurrence. Boku ga Aishita Subete no Kimi revolves around Koyomi Takasaki, a boy who lives with his mother after his parents' divorce. He tries to make friends at his new school, but his social awkwardness combined with a studious atmosphere means he's unsuccessful. One day, his classmate Kazune Takigawa approaches him and reveals that she's actually from World Line 85, where she and Koyomi are lovers.
Synopsis Kimi o Aishita:
It's about Koyomi Hidaka, a boy who lives with his father after his parents' divorce. He meets a girl named Shiori Satō in his father's research laboratory, and they begin a relationship that slowly blossoms into love. But everything changes when their parents decide to get married, and they decide to move to a parallel world where they are not half-siblings.
Finally, the novels can be read in any order the reader wishes.
Via: ANN