There are several Aerith dresses and or costumes to unlock, 3 to be precise and getting them all will count towards the Dressed to the Nines trophy achievement which requires you to Obtain all nine bridal candidate outfits.
In order to unlock them you will need to complete 3 different requirements including;
Light Pink Dress – Complete zer0 Side Quests during Chapter 8 – Budding Bodyguard
Pink Dress – Complete 3 different side quests during Chapter 8 – Budding Bodyguard
Red Dress – Complete ALL side quests during Chapter 8 – Budding Bodyguard
Thus this may require a couple of playthroughs in order to unlock them all. The dresses will take effect during Chapter 9 – The Town that Never Sleeps.
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