. "Mr. Simple / A-Cha" . "''A-CHa''" . "Mr. Simple" . . . . "ACHA" . "A-CHa" . . "\\\"Memories\\\"" . . . . "Walkin'" . "A-Cha" . "A-CHA" . . "Superman" . . "Oops!" . "Mr. Simple" . . "\uAE30\uC5B5\uC744 \uB530\uB77C (Memories)" . "\\\"Opera\\\"" . . . . . . . . . . . "A-Cha (Mr. Simple Repackaged)" . "Mr. Simple (as \\\"A-Cha\\\")" . . "fifth studio album of the same name" . . "\\\"Superman\\\"" . .