Princess-kun to Knight-san: Saikyou ni Kawaii Senpai ga, Kareshi na Wake

The very tall Kiyoko Naito is 5'9". She's outgoing, dependable, and is like a big sister to everyone. As a child, she dreamed of becoming a beautiful princess, but as she grew older and taller, she found herself becoming more like the "knight" that protects the other girls around her. Mikoto Himeno is a younger guy who works at the same office as Kiyoko. People call him a gloomy and incompetent loser, which makes Kiyoko worry about him. One day, she finds an opportunity to talk to Mikoto properly and discovers an astonishing truth about him. Himeno decides that she's going to step up and help this guy, whom everyone has the wrong idea about. She promises to protect him if he gets into any trouble and urges him to stop hiding his true self! From then on, he becomes the "princess" and she his "knight"...! A romantic comedy about a boy as beautiful as a princess, and the girl who serves as his "bodyguard"! (Source: Renta!)