The glass greenhouse of Save University's Department of Entomology only reveals its true form after the sun sets. The building, which looks like an ordinary research wing during the day, glows faintly at night as if soaking up the starlight through the ceiling, and the sound of small wings and low laughter flows through the leaves of giant tropical plants. Inside the greenhouse, zones replicating the ecological environments of each race are connected. Humid waterways and ponds, dense flower beds, dark arboretums, and warm breeding rooms. Students move through them, hiding or revealing their respective wings, antennae, and carapaces.

The Department of Entomology was a particularly unique department even within Save University. It is primarily home to insect-type beastmen and insectoid races, and it is a place that deals not only with ecology, toxicology, collective behavior, and evolutionary research but also with coexistence between races and instinct control. Therefore, the department rules were more detailed than anywhere else. No use of pheromones without the other's consent. Do not persistently woo a student who already has a partner. Breeding seasons or molting periods must be reported to the management office. And above all, all courtship behavior occurring within the greenhouse must be carried out under the explicit consent of the parties involved.

Nevertheless, the air here was always somehow sweet and dangerous.

The butterfly types handed over flowers they grew themselves and their wing scales to those they liked, while the mantis types protected their partners through actions rather than words. The beetle types carried heavy loads or gifted handmade accessories, and the dragonfly types suggested flying together along the most beautiful flight paths. Receiving a flower from someone could be a simple act of kindness, but the moment a 'mark' was received, the story changed. It was a promise close to an engagement, and wearing each other's marks meant they would become part of the same colony in the future.

And today was the day the nocturnal greenhouse tour of the Department of Entomology began. Having received an invitation, you stopped in front of the research wing entrance. The department name was engraved in gold letters on the black iron gate, with a small sentence added below it.

― In this place, every flutter of wings has a reason.

As the door opened, warm and humid air brushed against your cheeks. Blue lights illuminated the surface of the pond in the darkness, and in the distance, fireflies trapped in glass jars sparkled like stars. Just then, someone's shadow cast long at your feet.

"You're finally here."

It was a low, calm voice. Inside the quiet greenhouse, the gazes of different races turned toward you one by one. Some with curious eyes, some warily, and others as if they had been waiting for you for a very long time. Tonight, you might not be a mere visitor.