For some reason, I figure that this series could've had a pretty nice set-up by taking place in apocalyptic Japan, completely overrun by nature and infested by giant insects (killer animals, zombies, or honestly anything that poses as a threat in large numbers). Maybe something along the lines of Green Worldz or Gakkou Gurashi! comes to mind.
As for why exactly I figured an apocalypse would be a better setting is due to the facts that:
- All of the main characters are under 18, and all have the responsibility of piloting/working with advanced, military-grade mech-suits completely on their own, without any professional adult supervision whatsoever.
- There's not much of a good reason as for why these characters were chosen to do this. They even ask the heroine what exactly is so special about her, and aside from the joke answer being her large boobs, they gave some bullshit answer involving her "tough, fighting spirit" (or something along those lines)...
- I know that it's a really tough process, having to fully illustrate each chapter of an ongoing manga series with a deadline, but I gotta say, the art feels pretty damn lazy. I've come to instantly forget all of the side characters ever existing, as looking back at it, I notice that there's practically never any military personnel shown working with the characters at all, and the students around them never speak a single word. It's already as if NOBODY ELSE EXISTS IN THE WORLD THEY LIVE IN...
Otherwise though, this series uses so many textbook clichés and stereotypes that you could spot in just about every harem/ecchi/comedy/romance manga. Protagonist is a stubborn natural-born leader that's dense when it comes to girls and their advances. Heroine is a tsundere that beats up said protagonist whenever she gets into a revealing/awkward situation with him around. Whenever he compliments her though, she gets incredibly flustered so easily. The Genius Girl is incredibly young, yet cool + reserved. She bites the heroine's boobs whenever she gets jealous. The Lesbian Girl lusts after the heroine. Nuff said. The Ninja Girl is a fake little sister that looks up to the protagonist and simply wants to find a way to impressive him/make him happy. The Foreign Girl only cares about how she's engaged to marry the protagonist. Lastly, The Technology Expert // OnlyOtherMainMaleCharacter exists mostly for babbling techno-jargon to explain things to us. It's really just more bullshit though...
This series is completely void of offering anything new and compelling. There really isn't any story to follow, beyond the introduction of a new girl arriving into the harem. The art doesn't quite stand out in any interesting way, especially as it keeps giving us the occasional lackluster fan service scenes. The characters have no depth to them whatsoever. Worst off, the enemy takes on the form of giant insects, yet for some odd reason, there's usually less than 6 of them attacking at once, and they're always from the same species (group of centipedes, group of spiders, etc. etc.). Apparently, that's just pointing to more evidence of laziness...