Koroshiya S no Yuragi (殺し屋Sのゆらぎ, "Fluctuations of the Hitman S") is a Japanese manga series written and illustrated by Erika Funamoto [ja].

It was serialized in Shogakukan's shōnen manga magazine Monthly Shōnen Sunday from December 2018 to March 2021, with its chapters collected in four tankōbon volumes.

Written and illustrated by Erika Funamoto [ja], Koroshiya S no Yuragi was serialized in Shogakukan's shōnen manga magazine Monthly Shōnen Sunday from December 12, 2018,[2] to March 12, 2021.

[3] Shogakukan collected its chapter in four tankōbon volumes, released from June 12, 2019,[4] to May 12, 2021.

[5] The manga was nominated for the 2020 Next Manga Award in the print category.