Saburou Nobunaga

S1, E1: Saburou Nobunaga

Available on Crunchyroll
Modern-day high school student Saburou has no interest in history. He's sent back in time to the Warring States period, where he meets Nobunaga Oda, who turns out to look just like him. Brilliant but shy, Nobunaga asks Saburou to take his place.