Arisa Uotani

From Animepedia

Uo is best friends with Hana and Tohru. Kyoko Honda, Tohru's mother, influenced Uo to give up her life as a member of an all girl gang. Since then Uo has been very protective of Tohru. Her tough attitude and intimidating exterior serves to mislead many, but her close friends know that she is kind hearted and generous. Later on, in the manga, she falls in love with Kureno Sohma (the rooster) after having met him at her part-time job. Their (possible) relationship is apparently the reason for his sudden desire to leave the Sohma compund and Akito.