NA Localization:
She left nothing behind. She was clear-eyed about her fate from the start. Even just living was hard on her frail body. No matter how pleasant the weather was, for her, the season was always winter.
So she had no regrets, no lingering doubts. Once her role was complete, she was happy to disappear as if she'd never existed. She genuinely believed that.
"Ah, but...this sunshine is quite nice."
On that day, when the world was saved, when people and tomorrow returned to their rightful places...for a moment, when she closed her eyes, she caught a glimpse of something she'd never seen before.
"If tomorrow comes...I'm sure every day will be dazzling."
She fell into a deep slumber, holding onto that earnest wish. It was the proof of a life that should have vanished without a trace, like leaving a memory of one of her precious few hobbies to a dear friend.
Fan Translation:
She left nothing behind.
Speaking of the fate she was born with objectively, her weak constitution made it hard for her to survive, yet she remained calm no matter what, because to her, every season was winter.
That's why, she doesn't harbour any lingering affections or regrets.
From the bottom of her heart, she thought that it would be nice if she could vanish after she has accomplished her duty, as "something that that doesn't exist" like it was that way since the beginning.
"Ahh, but―――
The sunlight, it feels so nice."
That day was the day the world was saved, tomorrow returned, and the people brought back.
Just before she closes her eyes, just for a little bit, the girl saw something that she has never seen before.
"If tomorrow comes, I'm sure that it would be shining every day."
She fell into a deep sleep wich such longing.
Originally, hers was the symbol of a human life that was supposed to leave nothing behind.
But now, she hopes she can bequeath the few memories that she liked to her scarce friends.