|Chief Animation Director||Sakai Takahiro|
|Japanese Air Date|
July 8th, 2017
|← Soul||A Sunny Place →|
Yuki Yuna is a Hero: Washio Sumi's Chapter - Promise (結城友奈は勇者である: 鷲尾すみの章 - 約束, Yuki Yuna wa Yuusha De Aru: Washio Sumi no Sho - Yakusoku) is the third film of a trilogy based on the light novel Washio Sumi is a Hero. It aired on July 8th, 2017. The film also serves as episodes 5 and 6 of the second season of the Yuki Yuna is a Hero anime, which aired on November 3 and November 10, 2017 (respectively).
A rainstorm falls over the city as the class weeps over Minowa Gin's death. During her funeral, Sumi and Sonoko give her flowers to remember her by and Gin's younger brother Tetsuo breaks down and screams at the Shinju for letting this happen. Time stops and Sumi takes out her rage over Gin's death on the Vertex, screaming as she runs into battle. It is defeated in minutes.
The two are later praised by Aki-sensei for doing their job, but they still mourn Gin. In class, the two girls are bombarding with uneasy questions about their 'duty', and Aki-sensei gives them a day off. The girls spend it at a festival, shooting for prizes, eating food, honoring Gin with a small lucky cat and becoming closer as friends. During training the next day, the new system update is announced and the girls are introduced to their fairies. Sumi starts to move on from Gin's death, happy her family is alive and well. Their classmates have realized the true weight of the girls' duty and make a banner as an apology gift, which they graciously accept.
Meanwhile, Aki-sensei informs the parents on the system updates...and they are not happy. Sumi and Sonoko are sent to battle another Vertex and the girls are eager to test their new equipment. They end up standing across three Vertex. Remembering how Gin defeated three Vertex before her death, they transform. Sumi's bow has changed into a silver rifle, which she names 'Shirogane' after Gin. With their fairies protecting them, they enter Mankai for the first time.
Using the increased firepower, Sumi destroys a Vertex soul for the first time, and the explosion of lights confuses the girls. Until then, they'd merely damaged them to the point where the Shinju-sama banished them. Their mankai, which has a time limit, ends. Sumi finds she can no longer walk and Sonoko has lost sight in her right eye. They are forced to go into mankai again and during the fight the Great Bridge is destroyed by the Leo Vertex, making it impossible to use the Flower Calming Ceremony. The attack also forces Sonoko from her mankai, and her arm goes numb shortly afterward. She starts to understand there is a catch to using mankai.
After blocking an attack from the Leo Vertex, a fatigued Sumi asks Sonoko to handle the last one shortly before leaving mankai. Entering Mankai a third time, Sonoko destroys the Vertex's body and reveals the soul. Sonoko finds herself on the Vertex side of what was the Great Bridge and the soul floats through a barrier and vanishes.
Unwilling to let it escape, her Mankai ends and she gives chase, briefly getting the feeling that her "heart stopped for a second." Leaving the barrier she sees the world's true state and that the destroyed Vertexes are regenerating endlessly. Terrified, she puts her hand to her chest and realizes her heart isn't beating. Commenting "Ah... so that's how it works", she goes back to warn Sumi about Mankai.
Sumi, having powered down from Mankai, doesn't recognize her and asks where Gin is. Realizing that Sumi lost her memories because of the Mankai, she tells Sumi about the three of them while tying her ribbon around Sumi's wrist. An army of 21 Vertexes, led by the Leo, appear and Sonoko promises Sumi she would be alright before going off to fight them alone, unafraid as she knows she can't die.
In the next scene, Sumi awakens in a hospital room, unable to remember her name, and admires the strange ribbon on her wrist. The Great Seto Bridge is shown on the news in the twisted shape it will still be in during Yuki Yuna wa Yuusha. Confined to a wheelchair, the girl sees her new house and wonders about her family's wealth. A voice interrupts her, and a girl with red hair and a big smile introduces herself as Yuki Yuna. The amnesiac smiles and takes her hand in greeting, saying "I'm...Togo Mimori."
Character Appearances Edit
By order of appearances:
- Washio Sumi
- Nogi Sonoko
- Minowa Gin (body)
- Minowa Tetsuo
- Minowa Kintarou
- Togo Mimori
- Yuki Yuna