Koutarou and company are left reeling in the wake of Ralgwin’s mysterious disappearance, but he isn’t the only cause for concern anymore. Maki receives an invitation from Rainbow Heart, which brings the whole group to Folsaria. All seems well at first, but intrigue and danger are brewing under the surface in the supposedly peaceful land of magic. An old enemy rears his head after ages, renewing a fight that Koutarou hopes to settle once and for all. Will he be able to claim a definitive victory this time with the girls’ help?

After the attack underground, Koutarou and company return to the surface to regroup and plan their next move. They know Ralgwin will continue to come after them as long as he still has a hold on Earth, leaving them little choice but to mount an offensive of their own in an attempt to put Vandarion’s coup to bed once and for all. Fortunately, they have a little extra help on their side with the arrival of Princess Nefilforan, known throughout all of Forthorthe for her military and martial might.

Ralgwin is determined to avenge his uncle and carry out his mission of overthrowing the Forthorthian royal families, but it’s becoming increasingly clear that the villains he’s assembled to assist him don’t necessarily share his goals. The rebel leader is in for a betrayal he never saw coming, with far more at stake than he ever imagined. Meanwhile, Koutarou and the girls are preparing for the dramatic unveiling of the new Blue Knight, Forthorthe’s first knight-class battleship. A preliminary inspection of the craft turns up an unexpected development—a shadowy new face asking them to do the unthinkable.

Just starting high school, Koutarou is moving out on his own to take some of the burden off of his widower father. Lucky for him, he's found a room at Corona House. It has a great landlord, it's not too far from school, and best of all, it's dirt cheap. It really is perfect... except for the strange girls that keep appearing to try and take it over! But even as room 106 turns into a battlefield, Koutarou isn't willing to give up his apartment without a good fight. The invasion begins!

Harumi and Clan take a sentimental tour of Vandarion’s special territory, swapping secrets (and more!) in hopes of better understanding their respective relationships with Koutarou. Theia and Ruth also take a trip down memory lane as they review footage and data from their trip to Earth. Shizuka and Sanae likewise reminisce about the past while doing some spring cleaning. But then it’s time to kick back and cut loose! The whole gang heads to the beach, where the girls get their chance to shine bright!

After Clan and Koutarou are caught in the premature explosion of the Super Space-time Repulsion shell, they're blown clear across the universe to a most unexpected destination. Will they be able to put their fight aside long enough to cooperate and figure out a way to get back home? Along the way, they'll meet some strangely familiar allies and witness the start of a legend firsthand--just not the way they ever expected it to happen.

With Forthorthe on the verge of erupting into civil war like it hasn’t seen for thousands of years, Elfaria and the others do what they can to regain the trust of the citizens. But as it turns out, all of Forthorthe has their eyes on her, her daughter... and the mysterious knight in blue armor. Can they win the hearts of the people while trying to keep a very big secret from them? And with the vicious Vandarion plotting against them, it looks their bloodiest battle yet may be looming on the horizon.