User blog comment:FairyRaven/Fairy Tail Chapter 437: Magnolia, Review and Commentary/@comment-49.150.245.77-20150525105228/@comment-7418318-20150527072547

I think it wasn't so much because Mira was special, but because Mira was the last.

Lucy got more teary-eyed with each moment and Mira's "Welcome Home" was just the final bit to push Lucy over the edge and make her unable to hold back the tears.