I met Mio Tachibana because Saki waved me over.
It was a Thursday in the first week of February. I'd finished class early and was heading towards the cafeteria when I spotted Saki near the entrance, talking to a girl I'd never seen before.
"Itsuki!"
She beckoned me over.
"This is Mio. She's my friend. She's in Electronics."
"Electronics and Communication," Mio corrected cheerfully. "Four years of suffering, assuming I survive the assignments."
She never stopped moving. Even standing in one place, she shifted her bag from one shoulder to the other, looked past us at someone crossing the courtyard, then came back to the conversation.
"I'm Itsuki."
"I know."
I looked at Saki.
She smiled innocently.
"I've mentioned you."
"Good things, I hope."
"Some things."
Mio laughed.
"That's a dangerous answer."
"It was an honest one," Saki said.
I didn't ask what she'd told her. I was just glad she had.
We were still talking when a tall boy with short hair came over, holding his phone in one hand and a notebook under his arm.
"Mio, your friend is asking me for the answers again."
"He's not my friend. He's my classmate."
"That's worse."
He turned towards me.
"Kenta Mori. Computer Science."
I recognised him from lectures. He was in Saki's course, though we'd never really spoken.
His phone buzzed. He checked it, frowned at whatever it said, and put it away.
"Anyway," Mio said, "tell him what you told me."
"I'm not telling him."
"He's going to hear it eventually."
Kenta sighed.
"I guessed it."
I looked at Saki, who had already started smiling.
"Guessed what?"
"The murder film," Mio said. "The one with the detective and the family. He went on Saturday and he's been insufferable since."
"Because I guessed it."
"You guessed four things. One of them was right."
"That's how guessing works."
"That's not how being right works."
I laughed, which was apparently the wrong thing to do, because Kenta turned to me with the relief of a man who had finally located a reasonable person.
"Have you seen it?"
"Not yet."
"Don't let her tell you anything."
"I would never," said Mio, in the voice of someone who absolutely would.
We talked about it for a few minutes anyway, carefully, with Mio threatening to spoil it roughly every thirty seconds and Kenta physically turning away from her at one point. He knew more about films than I'd expected from someone who spent his breaks playing mobile games.
"Are you two going to do this all afternoon?" Mio said eventually.
"We've been talking for three minutes."
"Three minutes too many."
Saki laughed.
I did too.
But part of my attention had gone somewhere else, and stayed there.
They'd gone to a film on Saturday. That was all. Picked something, bought tickets, sat next to each other for two hours, then argued about it the whole way home.
It sounded simple when it belonged to other people.
◇◇◇
We found a table in the cafeteria.
Mio talked enough for all four of us. She complained about a lab instructor who seemed personally offended whenever anyone made a mistake, described a circuit that had refused to work until she'd replaced a component that turned out to be fine, and somehow connected both stories to a vending machine that had eaten her money in November and never been forgiven.
Kenta checked his phone every few minutes.
"Your squad again?"
"Final match."
"You said that ten minutes ago."
"This one's actually the final match."
"That's what you said about the last one."
"That was a different final match."
I watched them for a while without saying much.
They had the rhythm of people who'd stopped worrying about how they sounded in front of each other. Mio could say almost anything and Kenta would find the flaw in it, and neither of them appeared to mind. It occurred to me that this took time to build and that they must have had it for a while.
Most of my conversations with Saki had belonged to the two of us. I hadn't thought of that as a limitation until I was sitting at a table where it wasn't true. Meeting her friends made the shape of her life a little less distant. She had lunches like this, and arguments like this, in rooms I'd never been in.
I liked that she'd thought to bring me into one of them.
"Does he always do this?" I asked Saki.
"Apparently, being good at exams doesn't mean having self-control."
"I have excellent self-control," Kenta said. "I haven't played during class today."
"Because the professor confiscated someone's phone last week."
"That's unrelated."
Mio laughed so hard she nearly knocked over her drink.
When lunch ended, Kenta's phone buzzed again.
"They're waiting."
"Tell them to find a better player," Mio said.
"That's exactly what they're missing."
He left before she could answer. She followed him out, informing him at volume that she expected him to spend one afternoon that month doing something other than this.
He raised a hand without turning around.
◇◇◇
Saki watched them go, still smiling.
"They're fun."
"They are."
We walked back towards the academic buildings together. She told me a little more about Mio's lab classes, and I asked whether Kenta was always that serious about films.
"He's always that serious about something."
I laughed.
At the entrance, she stopped and adjusted her bag.
"There's a film I've been wanting to watch."
I looked at her.
"Not that one," she added. "A different one."
"Okay."
"We could go sometime. If you're free."
Something happened in my chest that I decided not to examine.
"Sure," I said.
"Okay."
She nodded. Then she looked at the door, and at the time on her phone, and said she had a class. Neither of us said anything about which weekend.
I didn't think much of it.
I had a lecture at two and an assignment I hadn't started, and it was the kind of thing people said to each other all the time.
◇◇◇
I thought about it again that evening, which I would like to record as the first warning sign.
Not the conversation itself. The last part of it. The way it had ended without ending, and how easy it would have been to say this weekend? while she was still standing there.
I had been three words away from an actual plan.
Instead, I'd said sure, and she'd said okay, and we'd both walked off to our respective afternoons like two people who would obviously sort it out later.
I remember thinking there was plenty of time. There were months left in the year, and then a summer, and then another year after that. The whole thing was so ordinary that it didn't seem worth hurrying.