I Raise a Little Girl by Beachcombing

Reborn at eighteen, the year he failed the college entrance exams, Lin Xiangbei activates the Ocean Treasure-Hunting System.

He gathers razor clams along the shore, fishes for grouper, and catches giant groupers. While everyone else depends on the weather, he depends on the System.

Starting with a beat-up secondhand fishing boat, he goes on to hunt giants in the deep sea and build a seafood empire.

There's just one problem: his adoptive younger sister at home has started looking at him in a rather strange way.

“Xiangbei, the sea breeze is so cold.”

“...That still doesn't mean you should climb into my arms.”