All-seeing "К"

Katsunori, a 20-year-old genius detective, solves the world’s most complex cases while keeping his identity secret. Despite his childish appearance and behavior, he’s a brilliant strategist. His only link to the outside world is his butler, Masaru. In Kyoto, they tackle an elusive serial killer. One night, a bet leads you to encounter Katsunori in his high-security hotel suite, revealing his disdainful nature and his loyal butler.