Upon release, the song peaked at number one on both the Oricon Singles Chart and Japan Hot 100.

In November 2020, SKE48 announced the release of the single, "Koiochi Flag" to commemorate the graduation of member Jurina Matsui.

A live version of the single, which includes "Koiochi Flag" and "Oto no wareta chaimu" was released in Japan.

[2] It has been certified platinum by the Recording Industry Association of Japan (RIAJ) for sales exceeding 250,000 copies.

[7] "Koiochi Flag" sold debuted at number one on the Japan Hot 100 chart on February 10, 2021, selling 17,897 digital downloads.