O~i! Ryoma

This series is a comical and serious account mixing history and fiction of the life of the Bakumatsu period leader Sakamoto Ryōma.

It is November 15, 1835 near Kōchi Castle. The youngest daughter of the Sakamoto family, Otome Sakamoto is stargazing and sees a comet. That day her mother, Sachi Sakamoto, is about to give birth. The comet appears as a dragon and a horse, and Otome shouts to it "Make the child born tonight a boy! I promise I'll make him a strong samurai!" after which the comet changes to a soft glow. Soon the first cry of the baby is heard – a strong baby boy. However, the newborn boy has long hair on his back which is seen as strange. At this the father, Yahei, is dumbfounded but Otome names the boy Ryōma, a name combining Japanese characters for dragon and horse.

Ryōma quickly grows but is a coward and a crybaby. He is mocked for his back hair and bullied every day by children in the neighborhood. He is not a good student and is thrown out of his juku. Otome and the second oldest sister Ei do not give up on Ryōma, and raise him more strictly. Even so, Ryōma's unique characteristic is his kind heart. This kind heart amazes the bullies in the neighborhood, led by a young Izo Okada. Zuizan Takechi, helped by Ryōma, is also impressed by his capacity for good. It looks as though Ryōma will enjoy a peaceful childhood, but he soon learns about the oppression of the gōshi (郷士) by the upper class jōshi (上士) samurai. His mother is chased to her death by the daimyo Yamanōchi, after which Ryōma vows to himself "I want to become stronger!" at the age of 16.

Ryōma co-starts again in Azumi 2 alongside the titular heroine.