In a near future, an illness called "Cagaster" made its appearance. It turns humans into insects. The story begins 30 years after the onset of the illness, in 2125. It follows the adventures of Kidou, a boy who fights insects.
Mushikago no Kagaster is a web comic that Hashimoto published on his official site "Chicken no Tamashii" under Hashimoto Chicken penname. In 2010, the author also started publishing the series as a doujinshi at Comic Market conventions, and published nine volumes in total. The series was officially published in a 7-volume tankoubon format by Tokuma Shoten starting on January 12, 2016 with the first two volumes, and next volumes published every next month. The series won French Prix Mangawa's Shounen Manga Award in 2015.
The series was also published digitally in France as Cagaster by Glénat Manga from Jun 18, 2014 to May 6, 2015 in a 6-volume format.