User blog comment:B214/High School DxD EX/@comment-3965848-20151201090719

Ya'know it's kinda clear that Kunou joins Issei's harem in the future, but considering how young she is and the guy's busy scheduled, she might not have his child yet.

Although if she did, it would probably be an infant so while it might not appear anytime soon, the child could still be mentioned.