Pichi Pichi Pitch

Mermaid princess Lucia Nanami has survived several villanious attacks that also threaten her fellow princeses, her relationship with her beloved, Kaito, and the health of the seven seas. When the evil Gackto captures one of Lucia's allies, she has no choice but to gather a rescue party and head to the deepest part of the ocean to confront her enemy. However in the deep-sea castle that is Gackto's fortress home, the magic of the princesses' perals won't work. How can a girl survive in the enemy's liar with no more powers than those of a normal teenager?