Her pigtails are just part of her stage outfit, they must die if she's going casual. Of course she can have her original outfit as an alternate.
The characters are more than just what they wear. Sakura is more than just "schoolgirl!" Mika is more than just "Wrestler!" ect, diversify them in a way where they are actually fighting in the street just by chance, especially years down the line after they have 'found themselves' so to speak, the teenage ones in particular, their 'thing' to stand out doesn't need to be so specific.
In her 20s, canonically Sakura doesn't freak out about being a teenager, finding Ryu or being a schoolgirl, she's a teacher who has a job and responsibilities in her hometown, but still loves to fight.
Likewise, Mika was introduced as a hot blooded wrestler type who overacts and cries because she is rising in the ranks, but that's obviously not how she acts when she's just walking around town out of the ring being a normal person, especially supposedly after years of that, she's done being a newbie, done being trained by her sensei and needing sponsors such as Karin to get anywhere close to her dream. All that is over with, so her character should reflect that
