For the planned anime series "Oedo Fire Slayer: The Legend of Phoenix" (Japanese "Hikuidori: Ushuu Boro Tobi-gumi") it was announced that the actor and singer Yo Oizumi will contribute the title "Kagerou" (German approximately "heat haze") as the ending theme song. This collaboration represents Oizumi's first work for an anime theme song.

The new title "Kagerou" was composed by the well-known composer Koji Tamaki. The lyrics were written by Yo Oizumi himself, who was inspired by themes such as human resilience and moving forward after loss. In a comment, Oizumi explained that when reading the anime's script, he was impressed by the story and its historical setting. The chosen song title is intended to create a thematic connection to the central motif of fire in the series.

The series is based on the historical novel "Hikuidori", the first volume of the popular "Ushūboro Tobigumi" series by the Naoki Prize-winning author Shogo Imamura. The book series began in 2017 and now comprises twelve main volumes as well as a collection of short stories. In 2021, the novel series received the Yoshikawa Eiji Bunko Award.

The plot follows Gengo Matsunaga, a once highly respected firefighting samurai in the Edo period, who, after a personal setback, builds a new firefighting team from social outcasts. This squad, mockingly called "Boro Tobi-gumi" (approximately "Ragged Ladder Brigade"), must defend against a series of mysterious fires, so-called "fox fires".

The anime production is being realized by SynergySP under the direction of Hiroshi Yasumi. The main role of Gengo Matsunaga is voiced by Yuichiro Umehara. The band Porno Graffitti is responsible for the musical opening (opening) of the series.

The announcement of Yo Oizumi's involvement is being received by fans as a significant contribution to the musical accompaniment of the series, as it reflects the central themes of rebuilding and hope, which are also embedded in the plot of the story.