K (Real Name: Claude K. Winchester) is Shindou Shuichi's former manager and now the manager for Bad Luck. K is aggressive in promoting the band--he even carries around a big gun and hand grenades. His concern is first and foremost Bad Luck, but in his shaping of the band's career, he ends up involving himself in Eiri and Shuichi's relationship. He is American, and in the original Japanese version, they played on the stereotype that Americans always have guns and will pull them out any time, any place. K often speaks English mixed in with his Japanese.
A resident of Los Angeles, and Ryuichi's former manager. His favorite person is Shuichi in his assumption of office as Bad Luck's new manager. His American jokes make no sense. He is fun-loving and has good intentions, but has a bad habit of turning his gun on anyone, anywhere to support his intentions.
- In the manga, it is revealed that K has a family; a wife named Judy Winchester and a son named Michael Winchester.
- K's last name may have been taken from Winchester Repeating Arms Company.
- His favorite food is hamburgers, tuna, sushi and chicken.
- Hobbies include cooking and shooting.
- His favorite phrase is "Big News!"
- After Grasper's breakup, he goes to his friend's place (presumably Ark), who is a picture book writer, and remembers playing and relaxing there.
- After making a mistake about Ryuichi, he went to Los Angeles
- While at Los Angeles, he served as the Chief Executive of the Secret Service, going by the name of "K."
- K has a strange excitement with loofahs and bubble wrap.