From Yaoi Is Life:

Featuring events such as Genma being immature and making Ryuusei drink more than he can handle, Himi begging Genma until his anger subdues, Asari teasing Shoui, and Waki trepassing into Raizou’s bedroom. This volume contains spin-offs of the -ZE- series. Most of these were created for autograph events and freebies during purchases. There's also a 26-page compilation of never before seen new material! No matter where you open it, this is a -ZE- full of love scenes! ♡