Tune in to the Midnight Heart (Mayonaka Heart Tune) - Season 1

When Arisu Yamabuki was all alone in bed at night, he was able to find solace in the voice of a radio host who went by 'Apollo.' However, one day, she simply stopped broadcasting without any explanation. Years then passed, and Arisu is now a second-year high-schooler. He makes it his mission to search for Apollo, as there is something he wants to tell her.