A baseball match was organized in Japan to promote the film where this insane match between creepy horror characters Sadako (ghost lady from The Ring) and Kayako (scary ghoul from The Grudge) stunned the audience.
Despite a rumour about Takako Fuji reprising her role as Kayako in this crossover, the actress stated several times on Twitter that she was not playing this representation of the character. Masaki Saisho, who played Kayako in Ju-on : Beginning of the End (2014) and Ju-on : The Final Curse (2015), is not appearing in the film either, making Rina Endo the fifth actress to play Kayako (counting Aiko Horiuchi who starred in The Grudge 3 (2009) and Kyoka Takizawa who played a younger Kayako in The Grudge 2 (2006)).
Elly Nanami is the seventh actress to play the role of Sadako, after Rie Ino (Ring (1998), Ring 2 (1999)), Hinako Saeki (Rasen (1998)), Ayane Miura (Ring: Kanzenban (1995)), Tae Kimura (Ring: The Final Chapter (1999), Rasen (1998)), Yukie Nakama (Ring 0: Birthday (2000)) and Ai Hashimoto (Sadako 3D (2012)) (without counting the Samara Morgan and Park Eun-Suh incarnations).
A certain number of events were held for the promotion of the movie. On Twitter, users can vote for either Sadako or Kayako as their favorite horror icon. The end of the vote were scheduled for the 17th of June. Two videos, one for Sadako and one for Kayako and Toshio, were uploaded on Youtube to appeal on the voters. Sadako won. In the end of May, a press conference was held to promote the movie. As it happened before for previous Ju-on movies, Sadako, Kayako and Toshio were present, in costumes, and stayed true to their roles.
A couple of other videos were released on the internet, featuring the ghosts of the movie teaching theater etiquette, such as not bringing recording devices or avoiding to take minors to see the movie, to promote the film.
For marketing purposes, several pieces of merchandise and goodies playing on the cute aspect regularly used in Japan were released, such as cup hangers, beauty masks and even a collaboration with the Hello Kitty brand. Other goodies were more traditional, such as T-shirts, key rings and doorknob hangers.
Rintaro Shibamoto is the seventh actor to portray Kayako's ghost child Toshio Saeki after Ryota Koyama (Ju-on: The Curse (2000) and Ju-on: The Curse 2 (2000)), Yuya Ozeki (Ju-on: The Grudge (2003), Ju-on: The Grudge 2 (2003), and The Grudge (2004)), Ohga Tanaka (The Grudge 2 (2006)), Shimba Tsuchiya (The Grudge 3 (2009)), and Kai Kobayashi (Ju-on: The Beginning of the End (2014) and Ju-on: The Final (2015)).