First University is a university, so the campus is mostly populated by eighteen or nineteen-year-old young witches, and after following Su Shijun to this school, Su Ya had trouble finding playmates of the right age.
Li Meng happens to be such a person--similar family background, similar age, same gender, the two little witches quickly became good friends.
Li Meng is not someone who keeps things under wraps and is steady, Su Ya likewise.
Although the Head Maid of Greenhill Mansion has repeatedly emphasized work discipline to the little fox lady, just like when the nannies ask Su Ya to "tuck her tail at her waist when standing" and to "cover her ears when combing her hair," the moment no one is supervising, she easily forgets all about those rules.
How comfortable it is to have your tail trailing behind when running, swinging left and right for balance! Why must it be tucked at the waist?