Each volume of this series finds out heroes desperate to make some cash and willing to accept most any work that will bring in a paycheck. In Vol. 4, they are signed on to help a destitute Japanese village become the Roswell, New Mexico, of Japan. While the three guys make crop circles litttle Makino checks out the supposed mummified alien corpse discovered by villagers fifty years ago. It is clearly the corpse of a monkey, but Kuratsu discovers an alien being trapped in the corpse, and so the teams sets to work.
As usual with this series, each episode takes on topical subjects in outrageous fashion, One of those touring exhibitions of plasticized human bodies leads the team into a hotbed of perverted science relating back to Unit 731, the WW II Japanese biological warfare initiative whose existence the nation denied until the 1990's. The wildest story involves the illegal imports for the exotic bug market which is causing an outbreak of suicides among collectors infected by a parasite that lives in a particularly desirable and illegal snail. The parasite does quite a number on its host's eyes and makes them want to fly. The results are predictably disastrous but it is all just nature taking its course.
The dialog throughout is profane and funny, and the visuals are consistently grotesque. Unfortunately I could find nothing from Vol 4 on the internet to reinforce that last statement.