"Then see you tonight, Miyuki!"
"Remember to come home early to make dinner. Don't be late..."
Waving to Herta, the little girl with long flaxen hair mounted her bicycle and rode away from the street outside their home.
"That thing... a human-powered, two-wheeled, single-person vehicle...?"
"What an incredibly backward means of transportation..."
Watching Herta Suzuko recede into the distance, the long-legged girl with the stunning figure had a strange look in her beautiful pale purple eyes.
Through her conversation with that younger sister, she had gained a preliminary understanding of the situation, as well as her current identity and circumstances.
Her name was Herta Miyuki, a second-year student at Water-Moon High School in Hare Sora City, and the school's most beautiful girl.
Since their parents worked abroad year-round, only she and her younger sister lived at home.
This world was called Azure Star, but its vastness could not begin to compare with her former home.
Its technological level was also rather backward. Even exploration beyond the stellar system counted as the cutting edge of space science.
Starting several decades ago, enormous disasters called Spacequakes had occurred frequently, killing hundreds of millions of humans and destroying vast stretches of cities and land, leaving behind only deep craters like those made by meteorites striking the surface.
The cause was the arrival of mysterious beings collectively known as Spirits, which triggered widespread spatial tremors and collapses.
These so-called Spirits were of mysterious origin and possessed extremely powerful combat capabilities and methods. Even heavy weaponry struggled to eliminate them.
At her younger sister Herta Suzuko's suggestion, they had moved to this fortified city, Hare Sora City, to avoid disasters and accidents.
"Forget it... I'll go to school first..."
"Since I'm not sure what will happen, I need to gather more information so I can