‘But I can see how it might work,’ Fuka said slowly, and everyone looked at her. Fuka glanced at Aki, sitting cross-legged on the floor. ‘Do you remember the last day of February, when there was no one else in the castle? It was just the two of us. We called the Wolf Queen, but she didn’t appear either.’

‘Yeah, I do.’

Ah, Kokoro thought. The two of them had had a strained relationship in the early days, but towards the beginning of March she’d noticed how they were getting on so much better, and she’d thought it quite odd, and wondered at what point they’d made up.

‘That must have been a leap year.’

‘Ah …’

‘Every four years there’s an extra day on the twenty-ninth of February. Aki’s is in 1992, and mine in 2020, but no one else had one. So for you it was suddenly the first of March, no?’

‘You’re right …’

‘We are the only two who gained a day.’

Fuka’s use of gained was a bit odd. As she listened, Kokoro began to work something out.

‘Holidays, too,’ she said.

‘Holidays?’

‘In January when we discussed what day the school opening ceremony was, we started talking about Coming-of-Age Day, remember? Subaru said it was on the fifteenth, and we talked about how in parallel worlds it would fall on a different day for all of us.’

Back then, Subaru and Aki had said:

Coming-of-Age Day is the fifteenth, isn’t it? I didn’t think it was a two-day holiday.

The opening ceremony’s one thing, but I thought Coming-of-Age Day would be the same for everyone.

‘So back in Aki’s time they hadn’t yet linked holidays with weekends? I’d heard that that’s how they used to do it.’

‘Is that really what happened? They moved the holidays?’

‘Yeah. It’s the Happy Monday System …’

‘Happy Monday?!’ Aki exclaimed, then burst out laughing. ‘What a silly name. Kokoro, are you playing games with me?’

‘No, I promise I’m not! I didn’t make it up. It really exists!’

Kokoro wasn’t used to being laughed at, and rose to defend herself. But at the same time she thought, Good – Aki’s quickly getting back to her feisty old self again.

‘One more thing – back in your day, Aki and Subaru, you went to school on Saturdays, didn’t you?’ Fuka said.

Kokoro was startled. The system of two days off per week.

Until third grade in elementary school, Kokoro’s school had every second Saturday off. And she’d really enjoyed having an extra day off every other week.