yellow plastic bucket used at public baths
Refers specifically to the iconic yellow plastic bucket with the ケロリン logo, commonly seen in Japanese public baths (sento) and onsen. The name comes from the pain reliever brand ケロリン, which was advertised on these buckets.
I fill the yellow plastic bucket with hot water at the public bath.
The yellow plastic bucket gives off a Showa-era retro vibe.