Samurai Swordfish

Edo 1863 Aisuke Kajiki a young blind swordsman is entrusted the son of his best friend Toramaru Sakakibara who is about to the Shoguns Samurai Unit and promises to train him well However after Toramarus death in battle Eisuke drowns in a river and is transported in time to presentday Tokyo Eisuke and his descendant Ryusei a college student go to meet Toramarus descendant Taiga a swimmer The blind samurais promise to his best friend in Edo is fulfilled 160 years later in presentday Tokyo through paraswimming