Ken Takagi (高たか木ぎ鍵けん, Takagi Ken?) also known as Lock Hero: Rock Lock (錠前ヒーロー ロックロック, Jōmae Hīrō Rokku Rokku?) is a Pro Hero. Ken is a very pragmatic and blunt man who is quick to judge whether or not someone is an asset. He is especially critical of newbies and young students, aware of the fact that they are possibly children risking their lives in dangerous situations. His infant son makes him more cognizant of the students' young age than the other pros. Inexperience often annoys him, though.