Inoue Risu said goodbye to her closest friends, Hideo and Serrulata—hopefully not for good. Ever since Risu's fifteenth birthday, the trio had spent countless days saving Etō-ku Ward from the horrors that emerge from the Jigoku Maw—a portal to the Fell Realms beneath Chīsai Prefectural Takeuchi Junior and Senior High School.

When their misadventures first began, they would call her Risu-chan, Monsutā no Sentōki. It was meant to be a joke; how could someone with such a cutesy name be a Battler of Monsters? But that's exactly what she had matured to become.

As they exchanged stoic farewells, Risu recalled how they vanquished the gremlin that was distracting the baseball team; when they exorcised the lustful tempter vexing the Contemporary Visual Media Club; their team-up with Timespace Helmsman Satoshi to defeat a giant interplanar bacteria-like thing, summoned by a disgraced chemistry teacher. In that period, they had bonded into nakama—true companions.

Risu felt hesitant leaving her pals behind after so long. But in her heart of hearts, she knew they could handle themselves if anything crazy were to happen.

True to her name, Serrulata had blossomed from a reticent bookworm and Linux enthusiast into a borderline Magickal Girl. By that point, she was able to tweak minor elements of reality as competently as she edits a line of code.

Hideo hadn't grown much taller since Junior High School, and he was still chronically fond of puns, quips, and one-liners, even in the most dangerous situations. But he was now far more adept in taking advantage of the environment around him, after months of freerunning and parkour.

Risu was giving little Hideo one final hug when her sensei Jairuzu beeped the horn of his decade-old Mazda Axela. The insistent honking no doubt bothered families having supper in the middle-class residential block.

Risu got into the passenger seat. As far as her Auntie Hime knew, she was off to a month-long study camp for gifted scholars.

"I already told you," Jairuzu admonished her, "We need to reach Kaikō-shi before midnight!"

"I don't understand why we can't just take the bullet train there."

"Unacceptable! That would put too many other lives at risk."

"Then just tell me what we're dealing with here, if it's so deadly."

"Trust me. For now, it is safer for you to know only what I tell you."

"So where exactly are we going?"

"Kojima Naval Base, just outside Kaikō City. We need to visit an old friend."

"Another one of those," said Risu, her tone deadpan.

Ever since the Sodanyaku Conclave appointed Jairuzu to be Risu's sensei, he would get periodic visits by all kinds of troublemakers from his past. He ignored the comment and kept humming along to Toshiko Akiyoshi Trio's Live at Blue Note '97, which seemed to be the go-to album on his weathered iPod. 

The jazz tracks continued playing as Jairuzu's car sped down the Chīsai-Kōchi Expressway. Shortly after passing the exit to Hatachi-shi, the sound quality began to deteriorate. Hideous static garbled the MP3 and interfered with the playback.

Risu gave Jairuzu a furtive glance.

"Just leave it," he said.

"But it sounds like..."

"I know how it sounds. Don't mind it."

Risu looked at the iPod's LCD. It was displaying an occult glyph that she recognized as some kind of ward. Then it changed to a single repeated phrase, over and over until it filled the entire screen: FIAT DENDO.

That's when ominous messages started flashing on the display of the GPS sat-nav unit:

WARNING!

DANGER AHEAD.

TURN BACK NOW.

OR ELSE.

"Look out!"

A kakashi scarecrow appeared out of nowhere in the center of the road. It seemed to materialize from thin air, right in front of the car. Jairuzu quickly hit the breaks but there was no avoiding it. The car drove headlong into the makeshift rattan cross outfitted with a loose-hanging robe and a sinister-looking mannequin head. It bounced off the hood, leaving a crack in the windshield, before sliding off the roof.

Risu and her mentor caught their breath. If there had been more vehicles on the road, it could have turned into a serious pile-up.

"What do we do now?" she asked.

"Nothing. We carry on," said Jairuzu. "If we stall any longer, then even more lives will be at stake."