Samurai Shodown 5 question

I happen to like this game alot…Haohmaru is my best character in CVS2…so i decided to pick this game up…and i really enjoy but there are very few people online…i know Suavion has it…but anyways, i was battling someone online and I dont know how but we enterd this mode where it tells you to tap buttons as fast as you can…can someone explain how this is done?

when your attacks meet at the same time you battle (tap the buttons) in order to make your opp. lose his weapon. The advantage to that is that every normal hit that the weaponless person takes will cause them to lose some life.