In an underground world where tunnels extend everywhere, even though they live in dark and confined spaces, people wear protective clothes and lead quiet and enjoyable lives. Patema, a princess in her underground village, loves to explore the tunnels. Her favorite place is a "danger zone" that her village prohibits people from entering. Even though she's scolded, Patema's curiosity can't be held back. No one ever explained what the supposed danger was. On her usual trip to the "danger zone," Patema faces unexpected events. When hidden secrets come to light, the story begins to unfold.

In a dystopian world, a young man vows to eliminate the giant humanoid creatures that threatens the remnants of humanity.

As the Trost District is reclaimed from the Titans, Eren is taken under the wing of Captain Levi and his squad, who decide to try and teach him to master his mysterious abilities.