Assemble Insert(1989)

The local law enforcement has a problem: the Demon Seed — a small but surprisingly capable gang with a charismatic leader. Their mecha body suits allow them to undertake spectacular crimes that regularly rampage the city and totally humiliate the police.

Desperate, the police have created a special branch just to deal with them. However, these unlucky few are not having any better results than the regular police and the public is turning against them. If they could just foil the Demon Seed once it would make their careers so much easier.

They just need a plan... luckily chief Hattori has come up with something the Demon Seed gang will definitely never expect. Hatched from chief's alcohol-induced mind, the plan is so bizarre that it just might work: Find the perfect crime fighter who is so powerful and captivating that even if they do not beat the Demon Seed gang, the public just will not care! And who could this person be? An idol singer of course!

The cute and innocent 14-year-old Namikaze Maron cannot sing or even dance, but she has the only talent the job really requires: superhuman strength! Now Hattori and his crew must mold her into the perfect idol singer and turn Maron into their ultimate weapon... but at what cost? Can she really survive the Demon Seed's onslaught?

(Source: Anime News Network)