User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170320082729/@comment-10330822-20170320174607

It may not be too weird. I feel in addition to different races and personalities, Issei is picking up different "types" of girls, and combos of girls. He already has the sisters, Koneko and Kuroka, so I wouldn't discount him getting a mother and daughter pair.