He said it the first time I stayed over at his house as a kid, after my parents had driven off to handle some emergency. I was seven, nervous, clutching a stuffed rabbit missing one eye. He didn't have children of his own, and his apartment smelled of old books and green tea. That night, he made me ochazuke for dinner, let me pick a movie on his tiny CRT television, and didn't complain when I woke him up at 3 a.m. because I’d had a nightmare.

Akira was only 12 years old, but her intellect and capabilities far surpassed those of adults. She was a product of a top-secret government program aimed at creating a being with the perfect blend of human and artificial intelligence. With her help, the world had made tremendous progress in sustainable energy, medicine, and space exploration.

Interpreting it literally:

The phrase implies a makeshift arrangement: not a planned vacation, but a necessity or a favor. That’s where the quiet sigh of “…dakara de na…ín” creeps in — the recognition that things might get complicated.