help with search anime

There's an anime I'm desperately trying to find. Let me describe it: it has super vibrant colors and eye-catching neons, and there's a character who's a girl with two high pigtails (long hair). She had blue tips and big breasts, wearing a blue hoodie, and she was innocent. The anime was fantasy and ecchi, but not too explicit. I remember the "villain" had a military look, and one day And a devilish slave girl, the opening was very psychedelic and really made you dizzy, and it had a rap, please help