Suzuki Osamu

Aikawa Ai is being bullied at school just because she's poor. One day, she's chosen to work at HelloWork "Child Hello". The job there can earn big money, but it is frightening. To protect her sickly mother and get rid of the fierce harassment from her relatives, Ai decides to earn money at "Child Hello". (from mangaupdates)

Hiro Okuyama is a fifth-grade elementary school student. He had been living a carefree life with his wealthy father. Until one day, his father suddenly disappears. What’s left behind is a stock account containing only 10,000 yen, and Kameyama, the guardian spirit of a golden turtle. To save his father, Hiro plunges into the world of stocks, aiming to turn a mere 10,000 yen into 100 million yen—! A never-before-seen juvenile money battle begins, where friendship, tears, and money collide!!