Age: 15-16 (immortal)
Height: 165 cm
Weight: 55 kg
Classification: Mystes, Crimson Lord, Human
Contracted to: Snake of the Festival
Title: World-Converting Ascetic
Yuuji, the central male character in the narrative, initially appears as an ordinary high school student. His life takes a dramatic turn when he discovers that he is already deceased and faces imminent disappearance. However, Yuuji possesses a unique treasure known as the "Reiji Maigo" within him, which restores his Power of Existence every night at midnight. This allows him to live on like a normal human as long as his Power of Existence doesn't run out before midnight. As the story progresses, Yuuji begins to unlock the hidden potential of the Reiji Maigo.
Deeply caring for Shana, Yuuji refrains from advancing their relationship due to his feelings of inadequacy as a Torch and viewing Shana as unattainable. He starts to see Shana from her former perspective, where he is just a Torch and she is a Flame Haze, causing him to distance himself from their previous closeness. Despite this, Yuuji remains a kind person who prioritizes others over himself, often confusing and irritating Shana, who is used to more selfish behavior from other Torches. His compassion draws Shana closer to him.
Accepting his fate without resentment surprises Shana, as most Torches would be devastated to the point of suicide. Instead, Yuuji uses his limited existence to perform heroic acts, believing his sacrifices will prove he once lived. While trying to maintain his ordinary life, Yuuji also assists Shana in battles to save Misaki City and its inhabitants.
Both Shana and Kazumi, who have feelings for Yuuji, decide to write him letters, hoping he will respond to one of them. Unfortunately, Yuuji disappears on Christmas Eve, and everyone except those aware of his true nature forgets about him. It's later revealed that Yuuji chose Shana over Kazumi, realizing his feelings had been there for a long time. To change Shana's fate, Yuuji voluntarily erases his existence on Christmas Eve.
Guided by a mysterious voice offering a chance to save Shana from the endless conflict between Flame Hazes and the Crimson Realm, Yuuji merges with the Snake of the Festival, a Crimson God. With newfound powers surpassing even a Crimson Lord, Yuuji joins Bal Masqué, becoming its leader. He confronts Shana in Misaki City, defeating her and claiming the Haridan from the Yoda Department Store.
Yuuji restrains Shana's powers using Tartaros and takes her to Seireiden. Along with some members of Bal Masqué, they travel to the rift between the human world and the Crimson Realm. Successfully awakening the Snake of the Festival's true form gives Bal Masqué an advantage in the war against the Flame Haze. Yuuji announces his plan to create Xanadu, a new world fulfilling Denizens' wishes without war or suffering. Despite some darker intentions behind this plan, Yuuji proceeds with creating Xanadu by sacrificing Priestess.
As Shana and her team fight to prevent imbalance in the future, Yuuji reveals his true intention to wait until midnight for the Reiji Maigo to refill, allowing him to control vast amounts of Power of Existence. Though Shana and the Flame Haze fail to stop the creation of Xanadu, Yuuji decides not to undo the law protecting humans placed by Shana.
Departing with the Snake of the Festival, Yuuji receives a chain-shaped key to Tartaros from the Strategist. The God of Desire expresses fondness for Yuuji's willingness to serve as a tool for his plan. Later, Spiral Organ grants Yuuji a crystal containing an Unrestricted Spell for restoring lost things and embedding a new spell into Azure, praising their collaboration.
In the final battle, Yuuji faces Shana and Margery Daw, gaining Sydonay's alliance. Activating the green crystal, Yuuji casts a spell on Kazumi, restoring Misaki City but regretting the inability to revive the dead. Yuuji declares his intention to teach Denizens and humans to coexist peacefully in Xanadu, even if it takes thousands of years, to be with Shana guilt-free. After being defeated by Shana and Alastor, Yuuji admits his loss and asks for Shana's forgiveness and companionship in Xanadu, which she happily accepts.
Embracing and kissing, Yuuji becomes a "solid existence," prophesied by the God of Punishment. Delighted by this revelation, Yuuji and Shana depart for Xanadu together.
