User blog comment:Jopjopjop/SlashDog/@comment-104.7.80.176-20150722154952/@comment-26527700-20150722213839

At best it was just a call out by the author to his earlier work (remember, the decision to include slashdog characters in dxd was a late addition). In any case, the Kanji used are different. For Koneko it's  塔城 while for Sae it's  東城.