Mermaid Melody Pichi Pichi Pitch

Mermaid Melody Pichi Pichi Pitch is a shōjo manga and anime series created by Michiko Yokote. The anime ran for 91 episodes and was produced by TV Aichi, divided into two seasons, aired in Japan from April 2003 to December 2004. The first season is composed of 52 episodes, while the second, entitled Mermaid Melody Pichi Pichi Pitch Pure, lasted for 39 episodes.

As the mermaid princess of the North Pacific (one of the seven mermaid kingdoms), Lucia entrusts a magical pearl to a boy who falls overboard a ship one night. Lucia must travel to the human world to reclaim her pearl and protect the mermaid kingdoms. Using the power of music Lucia is able to protect herself and the mermaid kingdoms from a growing evil force.

Love Etude (Season 2, Episode 9)
This episode introduces Lady Bat, a servant of Michel who can sing a song (Ankoku no Tsubasa) that put the mermaid princesses and other people in a trance like state, making them unable to protect themselves. In this episode the song is used on Luchia, Hanon and Rina.

It's Summer Vacation! Let's Gather, Everybody (Season 2, Episode 16)
During a fight Lady Bat used the entrancing song on Coco, Karen and Noel, and came very close to biting Coco before the rest of the mermaid princesses came and rescued their friends.

Love Fortune (Season 2, Episode 25)
Having problems in her relationship with Kaito, Lucia goes to visit a fortune teller to ask for advise, the fortune teller, who is actually lady bat in disguise, takes the opportunity to hypnotize her using a crystal ball, Lady bat start to interrogate her but before she could reveal any important information, Hanon and Rina snaps her from her trance by tickling her.