Tokumei Sentai Sirenger

Stardate 3000X: With the unexpected defection of the Lemon Rangers, Earth has fallen to the evil Demagogue. Fortifying mankind’s homeworld as a bastion of darkness, the leader of Demagogue has unleashed a new breed of genetic super monsters against civilized space, ushering death and destruction on a galactic scale. In an effort to stem the catastrophe, Galaxy Police has deployed the Siren Rangers to neutralize their traitorous comrades and defeat the mastermind of Demagogue before it’s too late.

[From Eroge Review]