Maria aims to learn more about her father's home country, and also how to become a proper lady for Rintarou.

Living in Meiji era Japan, Maria must hide the blond hair and blue eyes she inherited from her father out of concern over discrimination. But when a boy named Rintarou learns her secret, he can't help but say something: "You're...like a mermaid..." A dazzling historical romance awaits!

The love triangle between the sons of distinguished families picks up in this Meiji-era romance! Overcoming their difference in social status, Maria and Rintarou have vowed to elope. However, just before they depart, Rintarou's father-who has encouraged their engagement-falls ill!

Rintarou is back in Japan, and Maria is going to be his accompaniment at his return party. But when Rintarou's relative Chiaki starts flirting with Maria, he simply cannot hide his jealousy-and even tells Maria he's been waiting all this time to touch her! And amid the flurry of emotions is another obstacle: Rintarou's mother is against their engagement!

Although Rintarou continues to tease Maria, she feels a strange attraction to him. When Maria is invited to be Rintarou's partner at one of his family's high-society parties, not all is what it seems. Could this be a scheme by a third party? The Meiji-era Yokohama romance continues!