Kuroiso (黒磯) (26 years old), Mr. K in the Funimation dub, is Ai's bodyguard. He has dated Ageo. He is a member of the Secret Service, Ai-chan's bodyguard and driver. He always wears a black business suit and sunglasses, akin to Secret Service agents. He has never been seen without his glasses but by the reaction of Ageo in one episode it can be assumed that he is quite handsome.
He is very obedient to Ai-chan's orders because she blackmails him with disclosing the misdeeds he has done when he thought no one was watching (such as accidentally breaking one of her parent's priceless pieces of art and using super-glue to repair it) such as one time when Ai-chan ordered him to find leafs that has fallen during autumn (which result in him being hospitalized when he slipped while catching a beautiful leaf hanging on top of a tree branch). In one episode he shows photos to Ai-chan that a dog broke the statue and prevents her from blackmailing him. He hides while Ai-chan is in class (for example, in the top of the playfield's trees), but Shin-chan always finds his hiding place.
English: Christopher Sabat
Japanese: Fumihiko Tachiki
- His name is Kuroiso, Tochigi.