After a short break, the four girls of the Light Music Club resumed their climb toward the summit.
But the good weather did not last.
The once‑clear sky suddenly turned dark.
Heavy clouds gathered so quickly they were almost visible in motion, and within moments they blanketed the entire sky.
A muffled rumble of thunder rolled in the distance, and the air grew damp.
"Is it going to rain?"
Mio looked up anxiously, her slender fingers twisting together.
"But the forecast said nothing about rain today…"
"Just one more ridge, Mio, and we'll reach the rest station!"
Tsumugi pointed to a small wooden hut ahead, trying to sound calm.
"Let's hurry over!"
They had barely reached for their raincoats when fat drops began to fall.
In an instant—a torrential downpour.
All four were drenched like soaked cats.
Mio's long hair stuck to her face and neck, Yui's jacket turned unbearably heavy, Ritsu's cap lost its shape completely, and even the always‑elegant Tsumugi looked bedraggled, her carefully styled blond hair clinging to her cheeks.
"Run—!" Ritsu shouted, and the four dashed toward the hut.
Rain stung their faces; the now‑slick mountain path was treacherous.
The downpour intensified, visibility plummeted,
and thick mist spread through the slopes—only a few steps away shapes vanished.
Mio gripped Tsumugi's hand, terrified they would be separated.
Her heart pounded; besides the roar of rain she could hear only her own ragged breathing.
"Ritsu! Yui! Where are you?" she shouted,
but thunder swallowed her voice.
A flash of lightning lit her pale face.
When the three finally staggered into the rest station, the scene made them despair even more.
The hut was packed with hikers seeking shelter; there was no room at all.
They could only squeeze beneath the eaves, barely out of the direct rain, yet the icy mountain wind made Mio shiver uncontrollably, her lips turning bluish‑purple.
"Today really isn't a day for hiking…"
Ritsu shook water from her clothes, her teeth chattering; her trademark headband was soaked limp.
Suddenly Tsumugi's expression changed.
Her sapphire eyes swept the area.
"Wait… where's Yui?"
"Huh?"
Only then did Mio and Ritsu realize the ever‑energetic, pink‑haired girl was missing.
Mio's heart leapt to her throat; dread engulfed her.
"Yui… Yui's gone?!"
"She must've gotten separated in the fog!"
Ritsu stomped in panic, water flying from her hair.
"That airhead has no sense of direction—she once walked into the wrong classroom at school!"
KRA‑CHAK! … BOOM!
Lightning split the sky, followed by deafening thunder.
The rain pounded even harder, as though the heavens had been pierced.
With the trail this dangerous, searching would be reckless—but if they didn't go, Yui could be in mortal danger.
Horrible images flashed through Mio's mind; her stomach clenched with fear.
"We need help!"
Tsumugi pulled out her phone—no signal in the mountains.
She frowned in rare frustration.
"What do we do?"
Mio bit her lip hard enough to draw blood, her eyes darting between the rain curtain and the phone as she struggled.
At last she made up her mind.
"I… I have a way."
Under Ritsu's and Tsumugi's puzzled gazes, Mio opened a chat interface only she could see.
A mysterious group chat had appeared in her consciousness not long ago.
Its members came from different worlds, and the group owner, Ling Qing, possessed unbelievable powers in exchange for "trade."
Mio had only observed until now—deals always carried a price.
But for Yui's sake she had to try.
…
Akiyama Mio: "Is anyone there? I need help!"
Hiiragi Shinoa: "Oooh, another trade coming up."
Frieren: "What's wrong? I thought Mio's world was just an ordinary civilization—shouldn't be that dangerous."
Busujima Saeko: "Ordinary people still face problems they can't solve—even 'ordinary' problems."
Frieren: "Fair point. @Akiyama Mio, tell us what happened?"
Akiyama Mio: "We were climbing when a storm hit—one friend is missing!"
Akiyama Mio: "The rain's too heavy, we can't find her, no signal… She could be in real danger!"
Hayasaka Ai: "Lost on a mountain in a storm… that's dangerous."
Katō Megumi: "Shouldn't you wait for professional rescue?"
Julis: "Why panic? In my world this rain is nothing."
Yotsuya Miko: "It really is dangerous, though!"
Mabel: "Getting wet counts as danger?"
Shiba Miyuki: "@Mabel, for normal humans, hypothermia can be fatal."
Busujima Saeko: "Problem is we can't enter her world to help…"
Hiiragi Shinoa: "Only one option left~ @Akiyama Mio, you'll have to trade with Rei Ao‑kun~"
Marcille: "He's apparently the only one who can cross worlds."
Katō Megumi: "But think carefully about the price."
Akiyama Mio: "I… I know!"
Akiyama Mio: "If it saves Yui, I'll make the deal."
[Ding! Akiyama Mio has initiated a trade request!]
[Objective]: Find her friend Hirasawa Yui.
[Please choose trade terms.]
Akiyama Mio: "@Rei Ao, Group Master, please help!"
Rei Ao: "I've seen everything that happened."
He had just sent off Gabriel's sister Zelel; now another incident arose—things were hectic.
Rei Ao: "Let's be clear: you have only one thing you can offer in trade. Are you sure?"
Akiyama Mio: "Yes. Yui's safety is more important."
She had decided; she could never rest easy while Yui was in danger.
[Ding! Trade initiated!]
[Client]: Akiyama Mio
[Task]: Locate Hirasawa Yui
[Price]: "One‑time right to use Mio's body."