"Dear, You" was released as the theme song for the stage play Kare Phone, a romantic fantasy drama written and directed by Osamu Suzuki which premiered on October 4, 2018.[2] This marked Otsuka's first venture into composing a theme song for a stage play.
The song was written and composed and Otsuka, while it was arranged and produced by Seiji Kameda.[3] It originated from a melody Otsuka composed at the age of fifteen, which she described as her first-ever musical creation.[2] Reflecting on the song's origins, Otsuka noted that its youthful composition carries a dreamy and idealistic tone, characteristic of her early songwriting. The lyrics draw from personal and relatable experiences, evoking memories of her teenage years.[4] Upon receiving the offer to compose the theme song, Otsuka expressed initial apprehension, stating, "Honestly, I wondered if I was up to the task, but I wanted to embrace this new challenge and create something special."[2] Encouraged by Suzuki's request to capture the poignant emotions of a young woman's love story, Otsuka crafted a track that complements the play's bittersweet narrative.[2]
The song was broadcast in full for the first time on a Line Live streaming on July 21, 2018, as part of a special program dedicated to Kare Phone.[5]
The single was released on digital platforms on October 4, 2018, coinciding with the premiere of Kare Phone. The digital single includes a piano instrumental version of the song which was used in the production.[2]
"Dear, You" was ultimately included as the only new song featured on Otsuka's 2019 greatest hits album Ai Am Best, Too.[6]
