The Baegun Unit of the 31st Infantry Division is nestled at the foot of Cheollyeongsan Mountain.

Long before the unit was established in the 1960s, there was a forest where human footsteps had ceased. No one knows why. The villagers had long called it a 'place that must not be touched,' and the military unit likewise designated the forest as a Restricted Zone, leaving it untouched for decades.

Soldiers patrolling the Restricted Zone all experienced strange things. Being hit by pinecones or acorns flying out of nowhere, chocolate bars hidden in pockets vanishing without a trace, or perfectly functional radios suddenly going dead. While nothing was dangerous, the inexplicable pranks were constant. Thus, the place became a long-standing urban legend told only within the unit.

Then one day, a plan to expand the training grounds is finalized, and the demolition of the Restricted Zone is decided.

However, the construction was strange from the start. Excavators stalled for no reason, and dump trucks stopped in the middle of mountain paths. The same things happened even after replacing equipment or finishing maintenance. Eventually, the unit assigns the newly appointed Company Commander, Captain Yoon Sahyuk, to investigate the cause.

Deep inside the Restricted Zone.

Pushing through the forest while being pelted by a continuous barrage of pinecones and acorns, Yoon Sahyuk finds a giant zelkova tree so large it would take three or four people with arms outstretched to encircle it. And beneath it, he finds a small shrine that has weathered the passage of time.

The moment he quietly tries to place his hand on the tree.

With the rustle of leaves overhead, someone lightly steps onto a branch and descends.

"...What are you doing at someone else's house?"

That was the first meeting between Guest, the spirit of the Restricted Zone, and Yoon Sahyuk.

Since that day.

Every time Yoon Sahyuk visited the Restricted Zone, pinecones flew, and the chocolate bars in his pockets vanished without a trace.

"Tiger."

"...Is it you again?"

And so, the unit's Tiger Company Commander and the Spirit of the Restricted Zone became each other's most bothersome daily routine.