Basically there are these high school students that study in a special high school. Apparently, they fight with pods that have controls to control a small robot that is used to fight. I don't know who they're fighting though. There's also this special move that they use that's called 'full drive or 'OverDrive'. The main protagonist is a boy named Ban.
I saw the anime on a TV channel a few times but never had the time to watch it and when I had the time, it already ended.
I suspect this is Little Battlers Experience, originally titled Danball Senki. From the Anime News Network description:
Danball Senki tells the story of a world where kids battle one another using little robot figures called LBX (Little Battler eXperience). Yamano Ban, a young boy who desires to become an LBX Fighter like his friends, is forbidden by his mother from owning an LBX as his father was taken from them in an accident relating to LBX years ago. One day a mysterious woman approaches Ban with a suitcase and tells him the hopes and fears of humanity lie inside it, and when Ban opens it, he finds a strange new LBX Robot. He is soon attacked by organizations who want the data inside this robot, and Ban and his friends are dragged into a corporation war that spreads all the way up to the highest political positions of power in Japan, and the true origins behind LBX Battling which could change the entire political structure of Japan.
This was given as a stub answer in Anime: Teens fighting with little robots in their hands who shoot round bullets, which I found with a Google search for anime kids school fight "small robots".
