The 8:30 in-store announcement played, and Takana Mika gathered with her coworkers in the space next to the registers.

“Good morning.”

“Good morning.”

The employees responded in unison to the manager’s greeting.

This was Himawari Mart—a locally rooted supermarket in a small town with a population of 30,000.

After the usual brief morning meeting, there were still 25 minutes until opening. Everyone returned to their tasks of checking the store’s merchandise.

“Alright, let’s get to it.”

Just as Mika started walking after calling out to a coworker, the manager stopped her.

“Mika-chan, can you get the items from Warehouse No. 4 today?”

“Ah, sure. Got it.”

“As usual…”

Then, suddenly lowering her voice, the manager whispered into Mika’s ear:

“The black demon might show up, so don’t forget the insecticide and cleaning tools like always, okay?”

With a mischievous grin, the manager winked. Then, switching back to her normal tone, she called out to another employee passing by.

“Ah, Asako-chan, wait a sec! Anyway, Mika-chan, thanks! Just two boxes will do. Oh, and if you could clean up like usual, that’d be a big help. You’ll be at Warehouse No. 4 until 1:00, when your break starts!”

“Got it!”

Mika hesitated for a moment at the cleaning supplies station before choosing a bamboo broom and a stainless steel rake. She placed them on the cart along with the insecticide and headed out the back door.

This supermarket had three warehouses inside the store for different types of goods—and one more outside: Warehouse No. 4. Built by digging into the cliff of the nearby mountain, it was said to have been used as an air raid shelter during the war.

The reason Himawari Mart had managed to survive these tough times despite its small size lay in the secret of Warehouse No. 4. It stored the collection of the founder—the manager from two generations ago—who had run an antique shop in his youth. Starting as an antique dealer, he began selling vegetables and bread alongside his wares, which became the turning point that led to the establishment of Himawari Mart in 1968.

Now, it was mostly an ordinary supermarket, but on the shelves opposite the daily goods, there was a display case for the antiques collected by the founder. These were a big hit with certain customers, providing steady sales every month.

As usual, Mika unlocked the door and stepped inside. The warehouse had no electricity, yet it was dimly lit by some unseen source of light. The exposed rock walls still carried the unmistakable atmosphere of an air raid shelter. It was also surprisingly spacious—Mika had never even been to the very back.

She forced the cart over the entrance’s step, pushing it inside, then closed the door behind her.

Mika had been working part-time at Himawari Mart for six months now. Shortly after joining, she was assigned to Warehouse No. 4, and ever since, cleaning and retrieving items from here had been her responsibility.

“Alright, let’s get to work!”

Gripping the heavy stainless steel rake, Mika ventured deeper inside.

That said, when someone mentions a black demon, you’d normally think of a cockroach, right?

The manager had warned her—If the supermarket’s reputation takes a hit, we’re in trouble, so no matter what you see, don’t talk about it outside, okay?—which, of course, made sense.

After all, who would ever believe that there was a real, pitch-black, demon-like creature living in the warehouse?