Chichi to Tsuioku no Dareka ni (To My Father and to Someone in My Memories)

Chichi to Tsuioku no Dareka ni (To My Father and to Someone in My Memories)

This is supposedly the follow up novel to Yoru Sumino's "I Want to Eat Your Pancreas" (Although it is more of a short story than a novel) that was released only in Japan for people who went and saw the movie.