The female detective team Crimson Girls attend a convention to investigate a request.

Mitsu, Arisa and Makino enter the convention hall. But before they can retreat, the trap is sprung!
All three girls are drugged. Mitsu gets spread on a table and lubed for assault. Arisa gets wrestled
into submission by two men in a mesh ring. Makino's hentai assailant torments her until she
can't resist any more...

[From DLsite English]