When the "Jaleco" screen appears, begin pressing B, A, X, Y repeatedly. If you do it fast enough, a scrambled screen will appear. Wait until you hear a sword slash sound, then press Start. When the screen changes, press Down, Down, Down, Start. On the Options screen, select "Exit." This trick allows you to change the name of the game to "Rushing Beat."
Also, some of the characters will have different names and the dialogue will be in Japanese.