Himitsu no Chaiharo

Ai Aikawa is being bullied at school just because she's poor. One day, she's chosen to work at "Chaiharo," a Hello Work for children. 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 "Chaiharo."

(Source: Kodansha, translated)