February 12, 2025 • Experts analyzing the painting have several theories about why this unidentified woman has remained submerged for more than a century.

Many fans have even started discussing this on anime forums and some have even created their own versions of fan art revolving around it. Unfortunately, the anime never dives too deep into this, but ...

The story is set in the distant future. The land is ruined, and humanity establishes the mobile fort city Plantation. Pilots produced inside Plantation live in Mistilteinn, also know as the "birdcage.