Board Thread:General Discussion/@comment-25222488-20150511004756/@comment-86.161.150.216-20200803102958

If you can put emotions into someones brain, then technically, you could also put merories into someones head. The have the gear for it and Yui's memories are in Kirito's nerve gear.

Basically, all they have to do is have a biological child and give it Yui's memories using the nerve gear.