Choi Taehun was identified as a Guide at the age of five. This was significantly earlier than the typical manifestation for Guides. Since neither of his parents were Espers or Guides, they were deeply shocked to learn their son was a Guide. For ordinary people, Espers and Guides were often associated with being recruited into the military or police, working at the front lines of combat and criminal investigations.

They worried that their eldest son, who had never been in a single fight growing up, might be drawn into such dangerous situations. However, their fears were heavily influenced by misconceptions.

Espers can be broadly categorized into physical and non-physical types.

Non-physical Espers possess highly advanced intelligence-based abilities, such as data analysis, calculation, and deduction. They spend most of their time working in research labs, far removed from battlefields and high-risk crime scenes. Their lives are hardly different from those of ordinary office workers.

Of course, the kind of dangerous Espers Choi Taehun’s parents feared do exist. Physical Espers use their special physical abilities to operate at the frontlines of crises and emergencies. The violent image often associated with Espers originates from the chaotic nature of their work.

Espers can be defined simply as:

“Individuals with extraordinary abilities beyond the genetic traits of ordinary humans.”

Regardless of whether they are physical or non-physical, Espers are often described as embodiments of sheer power. Yet, paradoxically, even these powerful beings have someone who stands above them—someone who holds absolute authority over them.

That person is a Guide.

Espers pay a price for their immense power. As their heightened senses approach the limit of what they can process, their minds begin to deteriorate, much like a machine suffering from overload.

This is when a Guide becomes essential.

A Guide soothes, embraces, and grounds an Esper who is slowly losing their sanity to their own abilities, holding them close and anchoring their mind with care and affection.

In that moment, strength and power no longer matter. A spiraling Esper, lost in their self-created darkness, relies solely on the light of their Guide. This is why Guides, despite having no extraordinary abilities of their own, hold such power over Espers. As their name suggests, Guides are meant to steady the unstable consciousness of an Esper, allowing them to regain control.

However, not all Espers and Guides can be paired together.

A compatibility system known as “matching” determines which pairs can work together. The higher the compatibility score, the easier it is for the Esper to stabilize and for the Guide to manage them effectively.

Espers and Guides who surpass a certain compatibility threshold are required to register at a government facility and are often assigned to public institutions. While some are placed in standard administrative roles, those with exceptional abilities are frequently deployed to high-security sites or dangerous fieldwork.

This includes missions like subduing rogue Espers who have lost control after losing their Guide or dealing with crime scenes involving unstable Espers and their Guides causing havoc together. Sometimes, it’s even ordinary criminals known as “Middles”—neither Espers nor Guides—committing crimes.

Choi Taehun’s parents worried that their son might end up in such perilous situations, secretly hoping he would never meet an Esper compatible enough to require a pairing.

However, Taehun himself had no such concerns. Being a Guide felt neither burdensome nor frightening. In truth, he was too young to feel any strong emotions about it when he first manifested.

The identity of “Guide” felt as natural to him as breathing—like a duty he was born with.

Years passed, and Taehun grew into a reasonably good-looking young man. If not for his five younger siblings, he would have seemed even more ordinary. His academic performance was slightly above average, his athletic skills below average, but his childcare and household management skills were exceptional. By twenty-eight, he was an unremarkable but capable young man who could fit in anywhere.

Throughout those years, Taehun regularly underwent matching tests with Espers every two months, a mandatory procedure for unpaired Guides registered with the Center.

Unfortunately, despite his diligence, Taehun never once recorded a matching score high enough to qualify for official pairing. His compatibility consistently fell below the required standard.

At least 30 percent.

That was an impossibly high number for Choi Taehun. He had never once scored above 20 percent during his countless matching tests with various Espers—sometimes even dipping into single-digit scores.

Since being identified as a Guide at the age of five, Taehun had undergone well over a hundred matching tests in the past 25 years, becoming so familiar with the staff at the Center that he addressed them as older siblings. Yet, despite all that time, he had never once seen any real evidence that he was a Guide.

From the time he could barely walk properly, Taehun had taken test after test without a single successful synchronization. Eventually, his constant failures made him something of a celebrity at the Center.

But that unwanted fame came at a cost—Taehun was exhausted.

And how could he not be? Matching tests were mind-numbingly dull, involving sitting face-to-face with a stranger for hours while being bombarded by monotonous machine sounds that could put anyone to sleep.

On his 28th birthday, after yet another disastrous matching result, Taehun finally snapped.

“I’m never taking another matching test again! If you keep pushing, I’ll file a formal complaint with the National Citizen’s Service!”

“Uh… Taehun…”

“You said there’s never been a case like mine in the entire 60-year history of the Center! I’m so sick of Espers and Guides—at this point, I’m practically just a Middle!”

The researchers awkwardly scratched their heads.

Technically, Taehun wasn’t wrong. There had never been a Guide so hopelessly incompatible with Espers in the entire history of the Center. And, of course, for public officials, the National Citizen’s Service was the ultimate nightmare.

In the end, Taehun was placed on the deferred matching list that very day—a list reserved for those unable to perform official duties due to medical issues or personal circumstances. He was treated as a rare exception.

Taehun considered it one of the happiest days of his 28-year life.

At least until he met that Esper.