|Spoiler Alert: This page contains spoilers. Read at your own risk.|
The Okinawa Defense Battle (沖縄防衛海戦) was an event where the Great Asian Union attacked Okinawa in 2092. Miyuki, along with her mother Miya and her mother's Guardian, Honami, took refuge in the army's shelter. Due to internal National Defense Force conflicts with the Left-Bloods, they were caught in a dire situation. Under the effects of Cast Jamming, they couldn't defend themselves. When the Psion waves weakened, Miyuki activated Cocytus and froze the mind of one of the attackers, after which they were shot by the other attackers. Almost dying, Miyuki, Miya, and Honami were saved by Tatsuya, who used his innate ability Regrowth.
This enraged Tatsuya, causing him to use Mist Dispersal on the attackers, defeating them almost single-handedly. Tatsuya then resolved to drive away the invaders off the island.
|“|| Tatsuya, accompanied by the Onna Airborne under the command of Kazama, had driven the invading enemy to the water’s edge. Normally, it’d be 'Onna Airborne accompanied by Tatsuya'.
However that single petite magician who stood alone at the head of a solitary infantry platoon, his form hidden beneath a full-faced helmet and Armoured Suit as he annihilated the enemy, could only be seen as such by both friend and foe alike.
The battlefield was an utterly one-sided slaughter.
With their invasion force defeated, the GAA Fleet launched a retaliatory rail-gun assault. To stop the oncoming ships, Tatsuya used "Material Burst" for the first time to destroy them. Honami used her shielding magic to protect Tatsuya during the flight time of the sniper bullet, that Tatsuya used as the target for Material Burst.
- Miyuki started calling Tatsuya "Onii-sama" – starts giving him more respect rather than treating him as just her Guardian, and accepts him as her brother rather than a simple servant.
- 'Self determination' as a mindset became predominant as opposed to a management oriented society.
- This is the first time Tatsuya used Regrowth on others (Miyuki, Miya, Honami and later on the soldiers fighting against the GAA invaders).
- Honami died from overuse of her shielding magic while protecting Tatsuya, he was talked out of reviving her with Regrowth.
- Tatsuya subsequently joined the 101 Independent Magic-Equipped Battalion as Special Lieutenant Ooguro Ryuuya and became a(n unregistered) Strategic-Class Magician for Japan.