To unlock you must simply complete the story mode beating all eight opponents using Hisako on any difficulty earning any objectives.
If you want progress towards :
She has three objectives, and all can be completed in one run.
1) Beat story mode. Simply win all eight fights.
2) Catch counter every opponent. This means either use low or high Vengeance (
) to successfully counter an opponents attack in every match. Utilise her instinct if you are struggling.
3) Ultra combo Aria. Simply beat Aria with an Ultra in the final fight. Her ultra is
when Aria's health is reading 'danger'.