Intrepid tax investigator Ryoko Itakura sets her sights on the mysterious and philandering Hideki Gondo, a suspected millionaire and proprietor of a thriving chain of seedy hourly hotels, who has for years succeeded at hiding the true extent of his assets from the Japanese authorities. Itakura and Gondo soon find themselves engaged in a complicated, satirical battle of wits.

A school was built on one of the Gates of Hell, behind which hordes of demons await the moment they will be free to roam the Earth. Hiruko is a goblin sent to Earth on a reconnaissance mission. He beheads students in order to assemble their heads on the demons' spider-like bodies. Hieda, an archaeology professor, and Masao, a haunted student, investigate the gory deaths.