Shakugan no Shana Final Episode 21
One Reason
Name in Japanese 一の理
Rōmaji Translation Hitotsu no ri
Release Date March 2, 2012
Production Staff
Screenplay Hideki Shirane
Storyboard Takashi Watanabe, Hajime Horinouchi
Episode Director Toshikazu Hashimoto
Episode Navigation
Previous Shakugan no Shana Final Episode 20
Next Shakugan no Shana Final Episode 22
Theme Songs
Opening Serment by Mami Kawada
Insert None
Ending One by ALTIMA

One Reason (一の理 Hitotsu no ri?) is the twenty-first episode the anime of Shakugan no Shana Final.


Chorde manages to reach the World Egg, and rewrites the Psalm of the Grand Order, instead of destroying the World Egg as expected by Bal Masqué. Enraged, the Snake of the Festival demands a explanation from the Flame Haze on what they have done. Shana and Alastor announce their own plans for the paradise Xanadu, which is to create a law where the Crimson Denizens are not allowed to eat humans anymore. Yūji, and the Snake of the Festival resolve to oppose their interference with all their might, and Yūji orders Sydonay to stop holding back against their opponents.

Sale, and Chiara continue their fight against Mammon, and Dantalion while evading the Seeking Researcher's inventions. The remaining The Four Gods of Earth also continue their battle against their respective opponents despite having achieved their goal, but as Orobas, Leraje, Haborym, and Ribesal will learn, the Four Gods of Earth have a another wish than just the law that forbids eating of humans: The wish to kill as many Denizens who have consumed humans as possible to create a taboo against consuming humans for Power of Existence.

Elsewhere, Johann has a talk with Yoshida Kazumi knowing that his life is coming to an end. Because of this, he has formed a plan that will allow him and Pheles to continue on in another form. He also has a message for Wilhelmina Carmel from him and Pheles. Kazumi wakes up in the back of the Hyakki Yakō van, revealing that her conversation with Johann was not held in the real world.

While back at the Star of Darkness Castle that has been turned into the towering Saishuku no Shadan, Dantalion unleashes a experiment of terrible powers upon Sale, and Chiara.

Back at the Hyakki Yakō van speeding through the streets, Para discovers that he is no longer in control after Pirsoyn deploys his unique Unrestricted Spell upon them. They speed up the embankment around the Star of Darkness Castle, and find themselves mid-air just as an army of Servant cannons, and Denizen's open fire upon them. It would seem they have run out of luck, and high above them Yūji, and Shana witness the van exploding...

Characters in Order of AppearanceEdit

* denotes if the character debuts in this episode

Powers and Abilities UsedEdit

Unrestricted SpellsEdit

Treasure ToolsEdit






Cultural ReferencesEdit

Animation TriviaEdit

  • Near the end of the previous episode, Sydonay watches the Chorde rings hit the World Egg while being restrained by Wilhelmina's ribbons and in his base form. When he views the same event in this episode, he is not restrained and in Manticore form, rushing to Hecate straight afterwards.




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