Years ago, an interdimensional gateway opened and unleashed two colossal creatures into the skies above the Sea of Japan, visible to every nation along the coast. After annihilating the naval squadron dispatched to probe the anomaly, the pair then turned upon each other.
Observing the clash from Japan, researchers Joe and Marie Hayakawa were drawn into the breach. Returning to Earth, they assembled and released their findings in a celebrated volume called ''Day of Succession''. Twelve years later, the couple attempted another journey into that realm and never came back.
Siblings Ai and Yu Hayakawa resolve to seek their parents and the enigmatic Wonderland they once studied. Driven by stories of ancient portals, they plan a perilous expedition through forgotten tunnels, hoping to uncover secrets lost for centuries. In the desolate remains of a closed subway station, they await a train that will carry them beyond. Onboard they encounter Lisa Pacifist, who swiftly offers to help them locate their missing family. Will the trio succeed in finding Joe and Marie?
Gonzo Digimation Japan