More details on Haruka’s battle system:

Like Kazuma and the rest of the cast, Haruka can begin a street dance battle by speaking with people around Osaka. You’ll have to dance to a variety of music types, including hip hop, house, idol, jazz and rock.

As you battle, onlookers will “judge” you. The periodic judgement has an effect on your dancing. If viewed negatively, the dancer – either Haruka or your opponent – will feel pressure and will begin to lose strength. If your strength depletes completely, the battle ends.

The dance battles have “Heat Actions,” used in the same way as Heat Actions in the normal fights – build up a gauge and unleash the Heat Action when the time is right. Prior to battle, you can set up Haruka with actions.