The film serves as an adaptation of the Japanese novel by Arata Tendo, which follows a jaded and embittered homicide detective on the trail of murderous sex traffickers, who discovers new spiritual meaning in her life when she comes across a mystical young man (Ezra Miller) whose calling in life is to mourn the dead, who have no one to mourn for them. Tendo won the Naoki Prize in 2008 for the novel Itamu Hito (The Mourner). The book got a Japanese-language adaptation in 2015.

Casper Kiriya (Last Knights) is set to direct the film from a script by Robin Shushan (AMC’s Feed The Beast), Mike Marcus will produce for Echo Lake Entertainment, along with Kiriya. Production is planned for summer 2019.

Miller will be starring as The Flash in DC Universe’s stand-alone movie about the superhero character. Kiriya’s directorial debut was live action-CGI pic Casshern in 2004. Recent movies include Last Knights starring Clive Owen and Morgan Freeman, and Goemon, based on a Japanese folk legend echoing the Robin Hood tale. Former MGM Pictures President Marcus’s credits for Echo Lake include The Ward and You Kill Me.

Miller is repped by Paradigm, Hamilton Hodell, and Peikoff Mahan. Kiriya is repped by Paradigm. Shushan is repped by CAA and Stefanie Epstein Productions.