Kidou Tenshi Angelic Layer, Machine-Doll wa Kizutsukanai Recommendations
Angelic Layer and Machine-Doll wa Kizutsukanai (Unbreakable Machine Doll) share the similarity of involving battles using technological advancements. The main characters from both series have a partner whom they train to fight.
Both series take place in a school environment where there's a competitive atmosphere. The competitions bring forth both friends and rivals for the main characters.
There is also comedy, and the series' mechanics regarding the specifics of their technology are explained.