I just came up with a plot. If you plan on taking this serious then please join me, but if you feel as though you won't be as active, then please don't join (I didn't mean for that to sound mean). Tell me if you are interested by pm and I'll choose from there. 

Plot: There's an academy that trains children into becoming Rangers of Justice. Only ones with higher ranks become part of a special squad known as Sentai Ops, but most people call them Justice Power Rangers, because they control immense power. There're five in total, but rumor has it that there are more. 

3 high school kids find a girl in the woods unconscious. They take her in. When she wakes up, she tells them that, she isn't from their world, and that they'll be under attack by a force, that wants to take their planet and that the only way the can fight back is to use the power that she took with her, on her way to the planet. She shows them three crystals. One red, one black, and one blue. She tells them that the crystals choose their masters, and that she needs to find the ones destined to control the powers, in order to fight the impending evil.