Kajika

Kawakami Takeru's younger sister. In honor of her bravery, she complains to her brother who is only writing her. She falls in love with Yamato Oguna, but she kills her beloved brother by him, cuts her hair and heads to Yamato for her single revenge. She reunites with Yamato Oguna and tries to take her revenge, but can not swing her blade down.

(Source: MyWaifuList)