Nodoka is visiting her sister and brother-in-law (who runs the White Dragon), and Nodoka brings Ranko with her. Ranko is taking a tour of SDF-1 when she gets lost (the ship shifted the walls). After a time, Ranko falls asleep next to the Protoculture Matrix. A secret door opens and baths Ranko in a golden light that has changed Ranko. Ranko finds her way out (the ship helped). It has been only two hours since she has gotten lost. The next day is the attack happens.

NOTE:
Can you see a Veritech doing chi blast, Kachuu tenshin amaguriken, or hiryu shoten ha, with the boost of protoculture power. And on her off time working with Lynn.