Excuse plot summary, omitting the parts that are obvious:
Percival has a chikan/exhibionism fetish so he hires a chikan service (100% satisfaction guaranteed!). They have a capsule filled with our Magical Drug du jour, called EAF (Flame Emperor Anal Fucking). It imitates the nervous signals produced during orgasm and sends them continually.
After Percival passes out they carry him to a public bathroom.
When he passes out again (this can't be good for his brain...) they switch locations and start calling him cattle. The EAF comes out again and this time is injected into rectum and his urethra.
The last page of the comic proper says he got really hooked on the whole experience. Satisfaction guaranteed indeed.