Yuuki Yuuna wa Yuusha de Aru: Washio Sumi no Shou 3 - Yakusoku is an anime film that premiered in summer 2017, produced by Studio Gokumi.

About the production: the story comes from a light novel, the film runs about 48 minutes and its current status is "finished".

Its main genres are action, drama, fantasy, mahou shoujo and slice of life, with themes such as Female Protagonist, Henshin, Guns and Fairy.

On AniList, Yuuki Yuuna wa Yuusha de Aru: Washio Sumi no Shou 3 - Yakusoku has an average score of 79%, a very good score, and appears on 6,486 users' lists.

The franchise continues in or follows from: Yuuki Yuuna wa Yuusha de Aru: Washio Sumi no Shou 2 - Tamashii and Yuuki Yuuna wa Yuusha de Aru.

The third and final movie in the Washio Sumi no Shou trilogy.

Official synopsis from AniList.