If you liked the Infinite Stratos manga, the Anime-Planet community thinks you'd like:
Akuto Sai enters the Constant Academy for Magick Arts hoping to become a high priest and change the world for the better. But when the school's oracle declares his future profession to be 'Demon Lord', he finds himself feared and hated by the entire student population. Now, instead of making comrades and studying for his exam, Akuto finds himself fighting off monsters, bullies, and well-meaning classmates in various states of undress. If navigating a magical high school as a transfer student wasn't difficult enough, Akuto now has to deal with a cute android ordered to observe him 24-hours a day, the precocious attention of the flying, invisible and naked Keena Soga and the advances of the school's most popular girl. Will he be able to overcome his fate, pass his classes, and mend his friendship with the violent Junko Hattori, or will he succumb to his demonic destiny?
One guy, a harem and comedic antics mixed with action, stir well. Sift some tsundere into the batch, fold with the contents of a school life outside regularity (Infinite Stratos two parts mecha with excellent gym wear and Ichiban Ushiro no Daimaou with it's school of magical youngsters, two parts) and season with drama to taste. Results are a harem/comedy with action, a breakout character in the harem that's genre-savvy, and some badass moments.
If one finds that they enjoy the end results of one, they should make sure to taste the other.
It's your standard harem manga with the same concept, "plot twists", progression and what not. Setting might be diferent but it's still around the same bunch of charachters that are more or less your standard harem charachters... If you enjoyed one you will definitely enjoy the other...