Nasu no Yoichi  (c. 1169 – c. 1232) was a  samurai who fought alongside the Minamoto clan in the Genpei War. 

He is particularly famous for his actions at the Battle of Yashima in 1184. According to the Heike Monogatari, (The tale of the Heike) based on a historical battle between two top clans in 12th century Japan. The enemy Taira  placed a fan atop the mast of one of their ships, claiming it protected the ship from arrows, and daring the Minamoto warriors to shoot it off. Sitting on his horse in the waves, his target on top of a rocking boat, he nevertheless shot it down with only one shot. 
He is alleged to come from the Otawara region and there is a museum and Shrine nearby commemorating him..  The shrine was built in 1577 with renovations in 1641.The museum has his sword in the exhibition and there is a short film about his feat with the arrow and the fan.  It costs 300Yen for the whole thing…