Sister Knows Best

Aria Knightwalker is Erza Knightwalker's younger sister and King Jellal's best friend. Being the sister of a knight, and the king's best friend, she has certain privileges, but none of that really matters because she loves her best friend. However, she can't bring herself to tell him because of something that happened while he was trying to save the worlds. At least, until her sister gives her the help she didn't know she needed. Begins roughly one year after Edolas arc.