Rando struggles to be a good "big sister" to Rina as fate conspires to put him in one disastrous situation after another. When pants start coming off, and half-naked women start crawling all over him for the thinnest of reasons, Rando must use all his karate wiles to avoid being exposed as a complete weirdo. Meanwhile, will the mad Dr. Manabe succeed in his plan to remove the last remnants of Rando's manhood...or will Rando remove Dr. Manabe's brains with his fist?