She laid out the china cups and saucers on a small table in the corner of the room, and smiled, clearly anxious not to keep us too long.

Mr Yanagi halted the process of putting his tools away, always methodical. ‘Thank you very much,’ he said with a bow.

In less than five minutes the front door banged open.

‘I’m baaack!’ came a bouncy voice from the hall, and steps approached.

‘Yuni,’ called her sister, ‘the piano tuner’s here.’

‘Oh good! Glad I got back in time.’

When they appeared together in the room, I was taken aback to see that their faces were nearly identical. The only difference was that one wore her hair down on her shoulders, while the other had hers in two braids hanging just below her ears.

‘Have you already tried playing it, Kazune? If so, I don’t need to.’

The younger sister – who I now realized could only be younger by a matter of minutes – stopped in the doorway and looked over at Kazune.

‘No, you should definitely try it out. We like different things from our piano, you and me.’

The girl with the braids left the room again, while her sister with a slight bow explained that she’d be back in a moment. ‘She’s just washing her hands,’ she said.

The other girl was soon back, her hair loose now so I could no longer tell them apart at all.

Although they looked exactly alike, the piano was a completely different instrument in the hands of this girl compared to those of her older sister. A different temperature. A different humidity. The sound was buoyant, overflowing with richness and colour. Now I understood why Kazune had insisted her younger sister play. With such variation in style, it would take a little finessing to tune the piano perfectly for them both.

The girl suddenly stopped and turned around.

‘Can you make the sound any brighter?’ she said. ‘I’m sorry, it’s rather selfish of me to ask.’

She was a tiny bit solemn in her expression as she said this, and over on the other side of the piano her older sister looked equally serious. I wondered if she too was hoping for a brighter sound. On perhaps she was simply deferring to her sister’s opinion. The younger girl rose from her piano stool.

‘I think perhaps you adjusted it so it didn’t resonate as much? I think that suppressed the sound and made it a little darker.’

Mr Yanagi smiled and nodded. ‘I understand. Let me take another look.’