Unlock Karin's Alternate Costume:
When you have beat Neam Ruins the second time you get it from Roger.

Unlock Lucia's Alternate Costume:
Talk to Thomas when you have beat Lucia's optional sidequest. Unlock Anastasia's Alternate Costume:
When Kurando has the Jutendouji fusion speak to his mother.

Unlock Kurando's Ultimate Weapon:
Talk to Saki at the Inugami village after the movie at the platform with Kato. Saki will give you an errand at the Dog Shrine where you will find Kurbando's Ultimate weapon.

Anastasia 's ultimate weapon:
When you have collected all 5 silver angels go to Edgar at Petrograd.