Magia Record: Puella Magi Madoka Magica Side Story Vol. 2 (manga)

Their wishes will change their fates.
When a rift forms among the magical girls of Kamihama City, Iroha puts the search for her sister on hold to help the team reconcile. Normally, they're quick to patch things up, but the "Breakup Rule" rumor that's been going around has Rena worried. It could be just another urban legend, but what if it isn't? An apology could spell the end of their friendship-if not her best friend's very life!