According to Kawamatsu, fighting against the Kappa-ryu is like trying to swim against raging waters which makes full use of his Fishman strength to inflict powerful blows. When wielding his Soto Muso, Kawamatsu was able to blow away several men charging against him, taking them down with a single blow.
Menamu-gawa (滅南無川,Menamu-gawa?, literally meaning "Destructive Hailing River): Kawamatsu lunges toward his opponents, holding the blade's tip toward them and overwhelming them. It was first used against several Beasts Pirates guards in the Prisoner Mine.Namu (南無,Namu?) is a transliteration of Sanskrit नमस् (námas, literally "to bow") and it is used in Buddhist salutations or expressions of faith. In the VIZ manga, this is called River of Retribution.
Yorikiri (寄り斬り,Yorikiri?, literally meaning "Frontal Force Out Cutter"): Kawamatsu performs a slash and sends opponents flying away. It was first used against several Beasts Pirates guards in the Prisoner Mine.