It was released as a single by Sony Music Entertainment Japan on September 29, 2023, serving as the first opening theme for the 2023 Japanese anime series Frieren: Beyond Journey's End.

[9] A source for "Yūsha" is the short story Fanfare for Frieren (奏送, Sōsō), written by Jirō Kiso and supervised by the manga writer Yamada.

[10] Despite funky and upbeat sounds,[11] "Yūsha" incorporates the main character Frieren's emotional changes and memories towards the hero Himmel,[12] expressing the anime's lonely and melancholy atmosphere.

[13] Originally, the opening theme would focus on the worldview of Frieren's journey, but Ayase and Shuya Yamamoto, the duo's creative director, were not satisfied due to the song's "little too much emphasis on the atmosphere".

[14] Rockin'On Japan's Mie Sugiura praised "Yūsha" for the structure expressing the story of Frieren: Beyond Journey's End itself densely and interpreted to have a connection with Yoasobi's 2022 single "Shukufuku", an opening theme for Mobile Suit Gundam: The Witch from Mercury, highlighting the "meaning of life" and "the miracle that we have met".

[15] Writing for Real Sound [ja], Eriko Ishii admired the lyrics that look like the words popping out one after another from the anime's story and oriental-styled phrase.

She also praised Ikura's vocals, which "keeps running to the next melody without leaving any trace, and conveys a tremendous sense of speed, independent of the actual tempo.

[17] With three days of tracking, "Yūsha" debuted at number nine on the Billboard Japan Hot 100 for the issue dated October 4, 2023,[18] with 22,086 digital sales, 2,426,245 streams, and 5.2 million video views.