Books in the Airship series

"Students of the prestigious Tokyo Metropolitan Nurturing High School are given remarkable freedom--if they can win, barter. or save enought points to work their way up the ranks. After getting in a fight with students from Class C, Sudou is on the verge of expulsion. Ayanokouji and Horikita may have found a witness in Class D's Sakura, but she's reluctant to make waveAnd even if she did, would anyone trust the word of a Class D student?"--