Booyakasha!

Despite his flashy looks, Detective Kai Kaburagi has a surprising soft side. When tasked with finding a missing college student, Kai's search leads him to a host—Ruka. There's just one catch: Ruka vanished from Kai's own detective agency a year ago with a lingering "I love you" that left Kai unsure if it was genuine. Annoying and fickle, Ruka might be a pain in the ass, but Kai can't seem to abandon him. They have an unbreakable bond that can't be described with just "messy" dating back to middle school. Reunited with Kai, Ruka is ecstatic, dangling a lead on the missing girl in exchange for a very specific favor. When Kai reluctantly accepts, Ruka immediately quits being a host and bursts back into the agency.

(Source: Shinkosha, translated)