Sister Princess Episode 10 English Dubbed Episode Title:Do Your Best, Big Bro!.Episode Description:Athletic and dauntless sister Mamoru trains her “Big Bro” Wataru to swim. Despite her unflagging support and his best efforts, he decides to give up, but when he thinks delicate sister Aria is floundering dangerously in the pool, his race to rescue her enables him to learn the doggy paddle.