Shimoneta: A Boring World Where the Concept of Dirty Jokes Doesn't Exist (下ネタという概念が存在しない退屈な世界, Shimoneta to Iu Gainen ga Sonzai Shinai Taikutsu na Sekai), officially abbreviated as Shimoseka (下セカ) in Japan, is a Japanese light novel series written by Hirotaka Akagi and illustrated by Eito Shimotsuki.

A manga adaptation titled Shimoneta to Iu Gainen ga Sonzai Shinai Taikutsu na Sekai: Man**-hen[b] (下ネタという概念が存在しない退屈な世界 マン●篇) with art by Yuzuki N' was serialized in Mag Garden's shōnen manga magazine Monthly Comic Blade from March 2014 to February 2016.

In the dystopian future of 2030, the Japanese government is cracking down on any perceived immoral activity from using risqué language to distributing lewd materials in the country, to the point where all citizens are forced to wear high-tech devices called Peace Makers (PM) at all times that analyze every spoken word and hand motions for any action that could break the law.

However, Tanukichi quickly finds himself entwined with the perverted terrorist "Blue Snow" ("Tundra's Blue" in some translations) when she kidnaps and forces him to join her organization, "SOX", in creating and spreading pornographic material across the city as a form of protest against the regulations.

[10] A manga adaptation by Yuzuki N', titled, Shimoneta to Iu Gainen ga Sonzai Shinai Taikutsu na Sekai: Man**-hen (下ネタという概念が存在しない退屈な世界 マン●篇), was serialized in Mag Garden's Monthly Comic Blade from March 28, 2014 to February 5, 2016.