The Blind Daimyo Japanese novel

Ryūsaka Himawari was a mysterious lady in their region, but known as the woman of exceptional beauty—said by some few who witnessed. Even the Emperor called her the "Finest Flower of Sun Dragon" of their clan. Yet her face and title is a complete contrary of her character. She used to mess up and come out of their house, disguised as a male. This angered her father until he decided to send her daughter to a Sect. where they study etiquette and ethics. There she met a young man named Monomorie Nobu, a son of shogun who's supposed to be a daimyo but due to his blindness, they decided to let him study about ethics instead. Himawari find this man easy to tease which lessened her boredom in Iku Recesses. Days later, Himawari felt like she wanted to help Nobu reaching his dreams, which made her discover about this remedy to cure Nobu’s blindness so he could be sent to the Daimyo's sect and learn being a Samurai. Years passed and they met again by chance—you find out what's inside it's hard to think what to put next. Go read it!