Sister Breeder erobook will be on sale on April 29th
http://www.amazon.co.jp/%E3%82%B7%E3%82%B9%E3%82%BF%E3%83%BC%E3%83%96%E3%83%AA%E3%83%BC%E3%83%80%E3%83%BC-WANIMAGAZINE-COMICS-SPECIAL-%E6%AD%A6%E7%94%B0/dp/4862694225/ref=pd_sim_14_9?ie=UTF8&dpID=61xPg9eppiL&dpSrc=sims&preST=_AC_UL160_SR133%2C160_&refRID=1KKTHXY765ZP7P5SMAWV