Tail of the moon, vol. 1 (Viz Media)

Usagi is the granddaughter of the leader of a presitgious ninja village, but she's such a klutz that she's never made it out of the kiddie class. Frustrated with Usagi's lack of progress, her grandfather sends her to marry Lord Hanzo and have lots of ninja babies. But the lord has no interest in her or her childbearing potential! The path to love is never easy, and Usagi has some unexpected competition. It seems that another ninja clan wants to welcome Lord Hanzo into the family, and they've sent the beautiful and talented Yuri to win herself a wedding. Usagi won't be daunted aby her rival's looks and skills, but will Lord Hanzo's secret feelings for an off-limits princess be enough to send her away in despair?