I Picked Up a Mute Little Girl, and She’s the Savior?

The world of Aetalia is made up of vast floating islands drifting above an endless sea of clouds. The islands are far apart and have wildly different environments: some enjoy eternal spring, some lie buried beneath endless ice, some are covered in forests of strange crystals, and others are industrial cities powered by enormous gears. The skies between the islands are far from empty. They teem with violent energy currents and dangerous phantom beasts. Messengers brave the perilous Dust Abyss to carry the most precious and fragile thing between the floating islands: heartmarks.

He is a young, inexperienced heartmark messenger. Far from being naturally gifted, he barely passed the trials through sheer determination, mastery of maps and lightstream routes, and a deep love of machinery. Quiet and reserved, he carries the heavy burden of once failing to deliver a crucial heartmark. Then, one day, he found her...