I have been reading Fairy Tail's "Trouble Twins" 「トラブルシインズ」, and have gotten most of the way through the book. A pair of twins appear before Fairy Tail, and ask for help being reunited with their parents. They go here and there and have quite a few adventures. Somehow, they end up at the Eclipse Gate. My reading comprehension in Japanese isn't all that good, so I am not completely sure how Natsu, Erza, Lucy and Gray came to the conclusion of why they should go to the Eclipse Gate. Then, this is where I skipped ahead a little. Apparently, something comes through the gate. An enemy that they must defeat, and then also Romeo and Asuka (daughter of Alzack and Bisca), as adults. Apparently, they are the twin's parents. If I am reading this correctly, Asuka and Romeo of Fairy Tail end up as a couple and have children together.