MTL - Little Mermaid Dressed As a Scientist - Chapter 79

The youngest Wiseman of the continent, Chu Tian, has traveled 30,000 years back in time to the age of antiquity due to an accident.

Shao Ci was bound to the ‘Befriending the Most Powerful Person’ system. After crossing through, only then did he discovered that as long as a more powerful person emerge, this unscrupulous system will immediately change the ‘capture’ target….

- Description from Novelupdates

Orphaned at the mere age of seven and thrown out on the streets with no place to go. Kana lived the life of a street rat. She did what she could to survive from digging through the trash and stealing what she could. But even after almost ten years of surviving, her life still ended short.

Crossing to One Piece world, he became Roger’s younger brother.