Infinite Stratos 2 is the anime equivalent of a lobotomy. An anime so insipid, so devoid of intelligent thought that a trip to the garbage can would likely yield something more interesting. Maybe you'll feel dirty afterwards, but hey, at least you won't receive brain damage for it.
I struggle to think of a single good thing to say when describing Infinite Stratos 2. Even the absolute worst of the medium (from the infamous Mars of Destruction to the nonsensical Cipher) can at least be laughed at in their awfulness. Not Infinite Stratos. It is everything wrong with the harem genre and the anime industry as a whole, assembled into one cretinous pile of filth. You would need standards so low that they pass the Earth's core and leave the other side of the planet in order to appreciate this trash. Nothing went right. Everything went wrong. Hell, this is awful even by the first season's standards.
Allow me to describe one of Infinite Stratos' most asinine scenes. In the sixth episode, Charlotte finds herself in a situation where her panties have magically disappeared. Rather than simply tell Ichika the situation like any sensible person would, she convinces herself that lifting her skirt and directly showing him is the only way to get her point across. Ichika does as she asks and looks. Her response? "Pervert!"
Another scene involves Ichika being forced to take body measurements of all the girls in the school (which every single one of them is happy about for some incomprehensible reason). He closes his eyes, so embarrassed by female cleavage, thinking to himself that a measuring tape does not require eyes to see. His complete lack of understanding about human anatomy results in him fondling the girl. Every single member of his harem then appears out of thin-air and catches him in the act, screaming and assaulting him as the camera pans away.
Even from the very first episode, we know that a trainwreck awaits. The antagonist walks down a dark corridor and meets five soldiers armed with assault rifles. They open fire... and all the bullets somehow manage to land in front of her feet or behind her. She jumps into the air, pulls out two pistols and shoots them all with perfect accuracy. Yep. Even the most brainless of Hollywood blockbusters aim for better than this, but I suppose Infinite Stratos never cared for quality in the first place.
The final episode is the most brain-damaging of all. The antagonist's sidekick willingly reveals to one of the girls the location of a hidden bomb, and the main antagonist then unleashes a laser attack on thirty or forty armed mech soldiers, annihilating them all instantly. Of course Ichika (the most worthless soldier in the entire school) and the members of his harem can take her on in a one-on-one fight, however. As the final insult to the audience's intelligence, a deus ex machina unfolds, placed in direct sight of the enemy at the most convenient time possible. They then escape, and the story ends with a random onsen scene wherein Ichika passes out in the girl's bath. OK.
I do not know how a show so stupid could have ever been produced. Even putting aside the abysmal writing, the harem aspect (the anime's sole appeal) fares no better. The two new additions to his harem (Tatenashi and Kanzashi) suddenly fall in love with Ichika for no bloody reason at all. In the case of Kanzashi, all Ichika ever had to do was smile a lot and play the white knight role once for her to be head over heels for him. There are so many damn members to his harem that you may as well just throw in the entire school at this point. What do they even see in Ichika, anyway? He is one of the most insipid protagonists ever created, absent of any personality. The animators should have just drawn a rock instead - at least that way there would be one less thing to infuriate the audience.
Aside from having the intellect of a toddler, Ichika has the maturity of one, too. He is so adverse to any female contact (even visibly cringing in one scene where a girl's breasts rub against his arm) that you would ordinarily assume he is a homosexual. The fact that he has seven girls blatantly chasing after him and does not recognise it is a testament to how dreadful his characterisation is. A decent harem series would have the protagonist aware long before this point, if not already actively pursuing one of the girls. Future harem anime should take notes from Sora no Otoshimono and HenNeko, and treat Infinite Stratos like the plague that it is.
Unsurprisingly, the female characters are just as bad. Even the two with a brain (Houki and Charlotte) inevitably fall victim to the show's abysmal writing. The most obnoxious is by far Cecilia, her voice so excruciating that it would be more appropriate in the 9 Circles of Hell. Lin on the other hand has about as much presence as a shadow while Kanzashi lacks any sort of personality or defining feature except "has glasses".
Infinite Stratos 2 is terrible even from a technical perspective. All of the action scenes are rendered in low-budget CG and many times the characters' faces will look as if they were drawn by a 10-year-old with a cheap "How to Draw Manga" textbook. The soundtrack is also rubbish and comprises mainly of elevator music and a tuba endlessly making the same two-three notes. During the action scenes, the music is so turgid and over-dramatic that it almost becomes hilarious when combined with the infantile dialogue.
It is rare to find an anime as bad as Infinite Stratos. It is the exact kind of tripe that gives anime such a bad image in mainstream society. Regardless of whether you enjoy the harem genre or despise it, absolutely nothing of value will be found here. Even as mindless entertainment it fails miserably. Avoid it like the plague, or better yet, convince yourself that it doesn't even exist. You will save yourself some sanity that way.
If this is the future of the anime industry, then god help us.