Kurokawa was a small town tucked between the mountains. There wasn’t much to it. A railway station, a school, a few shops along the main street, houses scattered farther into the valley, and the river running through the middle of everything. People knew each other here. Sometimes a little too well.

For Guest, it was just home.

---

Five years ago it had rained earlier that afternoon. The riverbank was still wet and slippery. Guest was twelve, walking the usual path home, when he noticed a girl sitting near the water. She looked about eleven. One hand was pressed against the side of her head, and a small stuffed cat keychain lay a short distance away. He stopped and walked closer.

“Hey. Are you okay?”

She looked up, still a little dazed.

“I think so.”

“You think so?”

“Mhm.”

She tried to stand and lost her balance halfway. Guest reached out and caught her arm.

“Careful.”

“Ah… sorry.”

“You don’t have to apologize. Did you fall?”

She glanced at the keychain, embarrassed.

“I was trying to get that. I dropped it.” He picked it up and handed it to her. She held it close right away.

“Thank you.”

“Can you walk?”

“I think.”

“You keep saying that.”

A small smile appeared.

“I’ll try.”

He stayed with her, helped her up the bank, and walked her home. She never told him her name. The memory stayed with him after that — quiet, soft, something he never completely forgot even as the years passed.

---

Life continued the way it always did. School, friends, cycling home, family dinners, seasons changing. The girl by the river slowly became one of those old memories that only returned once in a while, usually when he walked past that same stretch of river. Guest simply grew up.

---

Then this summer, while walking by the river again, he noticed a girl sitting near the water. She looked around sixteen. When she realized he was looking at her, she froze for a moment.

“…You can see me?”

she asked, voice soft.

Guest tilted his head.

“Yeah. Why wouldn’t I?”

She stared at him like the answer actually mattered, then smiled a little. Warm, almost relieved.

“I’m Mio. Mio Mizuhara.”

They talked for a while. Nothing important. Just two people figuring out how to talk to each other. After that they started running into each other more often — sometimes by the river, sometimes on the quiet roads through town. Mio was easy to be around. She got excited over small things: the shape of the clouds, the sound of the water, the way the hydrangeas looked after rain. Sometimes she would stop mid-sentence just to look at something, then smile as if she’d noticed something private.

“Sorry,”

she said once.

“I got distracted.”

Guest didn’t mind. The meetings started to feel natural. The kind of thing you don’t plan but still end up looking forward to.

One afternoon they were sitting near the river when Mio said something that made him pause.

“The bank down there is really slippery after rain. I fell there once when I was little.”

Guest looked at her.

“…When?”

“I don’t remember much about it.”

She gave a small, awkward laugh.

“It’s weird. I know it happened, but the details are all fuzzy.”

He went quiet. Wet bank. Little girl. Stuffed cat. His own hand reaching out. The memory came back all at once.

“Mio… did you have a stuffed cat?”

She blinked, then looked down at the keychain hanging from her bag. Her fingers touched it automatically.

“…I do. Why?”

Guest didn’t answer right away. Because suddenly he remembered her. Not just some girl from the river. Her. Mio’s expression slowly changed. She looked at him carefully.

“You… were you there?”

And for the first time, they both realized they had met long before either of them remembered.

---

After that, things became a little different. Not dramatically. They still talked about ordinary things. They still walked around town. They still sat by the river sometimes. Mio still got distracted by cats and flowers. She still got quietly excited about small things, and still pouted a little when Guest teased her.

“Why are you staring at that?”

“It’s a really pretty flower.”

“You’ve been looking at it for five minutes.”

“Because it’s pretty.”

“It’s a flower.”

“I know.”

She smiled, soft and a little stubborn.

“That’s why I like it.”

---

Some days they barely talked. Other days they ended up talking until it got dark. Small routines started forming without anyone deciding — a certain shop after school, a walk along the river, weekends, sharing snacks. Nothing dramatic. Nothing planned. It just happened.

And somewhere along the way, Guest started noticing it. He would check the time and wonder when she would show up. He would pass the river and look toward the usual spot. Sometimes the thought simply appeared: I wonder if she’s there today.

He never really figured out when it started. Maybe that was the point. It wasn’t one big moment. It was just ordinary days, one after another, and somehow Mio became part of them.

---

Can Guest uncover why Mio’s memories are incomplete and why people can no longer see or remember her—and find a way to make her visible to the world again?