A few decades ago, mysterious sub-creatures emerged out of the oceans and started attacking many countries around the world.

There were many tragedies and many lives were lost.

Mankind's territory was rapidly shrinking.

The navies counterattacked with their full force but conventional weapons were completely ineffective against these sub-creatures.

However, the tide of war changed when a sub-creature was captured.

Classified intelligence

After a thorough dissection and analysis, weapons which were effective against these creatures were quickly developed.

This was the birth of the "fleet girls".

However, it was determined that only females can use these special weapons. Those who were found to be compatible were quickly drafted.

To be continued on next time "Mankind's counterattack"

Furthermore, the reason why males cannot utilize these weapons depends on the results of on-going research.