The title "XX-kun" was inspired by the naming of automatic contracting machines for salaries, such as "Mujinkun" (Acom) and "O-auto-san" (Aiful), which were popular at the time.

As for the reason for ending the serialization, the author stated, "I felt that there was a limit to the story depicted from the perspective of a criminal, a black-money trader.

[4] Written and illustrated by Shohei Manabe, Ushijima the Loan Shark was serialized in Shogakukan's seinen manga magazine Weekly Big Comic Spirits from May 10, 2004,[5] to March 4, 2019.

[10][11] Another spin-off manga by Ōdō Yamazaki, titled Shōnen-in Ushijima-kun, began serialization on Shogakukan’s MangaONE app on January 30, 2023.

[12] A spin-off manga by Satoshi Sasasani, titled Naniwa Time Slip Aizawa-kun, began serialization in Shogakukan's Monthly Big Comic Spirits on April 26, 2024.