User blog comment:B00m666/Highschool DxD - Question about Issei/@comment-1359322-20131204005537

There's no doubt that Issei loves Rias as much as Rias loves Issei, he has proven that throughout the series. As for the other girls, Issei cares a lot for them since he considers them his comrades. Well though he's starting to get closer with them after overcoming his fears and becoming a couple with Rias.