The Pianist and the Cat Beneath Yukinoshita

[The main story is complete] "As for the future, I want to become a strong, independent woman."

The four-year-old girl spoke with conviction. When she turned around, her eyes lit up, and she reached out to tug at the sleeve of the person beside her.

"Then can I marry you, Brother Naoya?"

"Mm, sure."

After graduating from university, mastering the piano, and becoming an expert at all the household chores, Naoya Izumi returned to Japan. When he went looking for that little girl from back then, he realized there was one very important problem.

That little girl from back then...

What was her name again?

P.S. One-on-one romance, no harem.