Halo 5 Guardians: Its a Love Story!

Cortana had a choice remember? Dr. Halsey told her she could be implemented into any Spartan and she choose John 117; she liked Master Chief from the beginning that is why Master Chief is going crazy to find her; Halo 5 is a epic love story.

Master Chief and Cortana will be connected forever throughout the Halo lore! It all makes perfect sense