Mermaid Melody: Black Beauty Sisters: Sheshe and Mimi.

 Sheshe and Mimi are collectively known as the Black Beauty Sisters and worked as servants for both Gaito and Mikeru.  The pair often clashed with the other minions they served with. They were extremely arrogant when under Gaito, but much less so under Mikeru.  The duo were originally Angler Fish and fear being turned back into them.

First up is Sheshe.  She is the older of the siblings and wears red.  She is more condescending and aggressive than her sister. 

Next up is Mimi.  She is the Younger of the sisters and wears blue.  She is much more childish than her sibling and enjoys the destruction the pair cause.  In episode 27 of Pure she inadvertently befriends the Mermaid Princesses, leading her to be unable fight them after learning their identities in episode 33.   Mimi likes to pop bubble wrap when stressed.