Tail of the Moon Chapters

From Wikipedia:
The story takes place in the Tenshō Era of Japan. Usagi is a bumbling ninja-in-training in her village in southern Iga. Since she is such a terrible ninja and has made no progress, though she is already fifteen, her grandfather gives her a special mission: to go to Segachi and marry Hanzō Hattori, the leader of the main branch ninja family.

Mamezo, Usagi's longtime friend and companion, accompanies her on her trip to Segachi. Once they arrive it becomes apparent that Hanzō has no intention of marrying anyone, and worse yet, it seems Usagi has a much more refined rival. It is clear that as Usagi spends more time with Hanzō, she is growing on him, though the fact that he is constantly bombarded with new potential brides makes Usagi self-conscious.