Police arrested a 24-year-old factory worker Friday on suspicion of drowning her 2-year-old son in the bathtub of their apartment in Miyakonojo, Miyazaki Prefecture.
Mari Kaneda owned up to drowning Hiroki in the bath Thursday evening, saying she found child-rearing to be a burden.
According to police, Kaneda told her mother, who visited her apartment shortly after the incident, that Hiroki had drowned in the bathtub. She then called an ambulance.
The boy was confirmed dead later in the evening. Police arrested Kaneda after she confessed to killing her son.
Kaneda has repeatedly consulted with officials at a child consultation center and the Miyakonojo municipal office. She once told teachers at a nursery that Hiroki attended that she did not want to see her son's face, police said.
The woman and the child moved to the town this year and lived in the apartment by themselves, they said.