The easiest way to achieve this is to have Jiro join you AND send Mei to look for Midnight.
The hard way is not having one of the above or both, while choosing the right combination of teammates to avoid as many fight as possible on the way.
I was more on the fact dose the mall rescue event just happen or do you have to do something special after finishing everyone's events
Mei is always busy I finished all since all has nothing to do I finished the mall rescue too what do I do since mei is always busy
