King of Pain ~Inga Ouhou~ (因果応報) is the twenty-third studio album by Japanese metal band Loudness. It was released on May 19, 2010 only in Japan and marks the full-length debut of drummer Masayuki Suzuki. Guitarist Akira Takasaki would later say King of Pain was focused on featuring Suzuki. The album reached number 21 on the Oricon chart.
The album shows a return to standard-tuned guitars and bass, and according to some fans, a return to their 1980s sound.