The May 16 release date for the given anime film has been postponed due to the coronavirus outbreak in Japan, it was announced on April 13 on the official website of the anime series.
The given anime film was announced at the end of the TV anime broadcast of the adaptation of Natsuki Kizu’s manga series.
The official website noted that advanced tickets for the film will still be valid for whenever the anime film is released, with the date being announced at a later date.