User blog comment:B214/Question and Answers 6/@comment-2601:87:8300:20D0:F4DA:FD62:A4D3:B4B4-20190621141221/@comment-38340421-20190711194725

Sorry but it's pretty much been confirmed with the vision Issei was given. She was amongst the group of future waifus to be married to him in the future. Plus it was stated there could be a few more, but weren't shown because Issei hasnt' met them yet.