Etsunaga Inoue's daughter is two weeks old and in critical condition at a hospital with internal injuries. She was taken to the hospital by her father, a 37-year-old decorator, who was arrested after staff concluded her injuries were the result of being kicked and punched.
Police in the town of Maebashi in central Japan believe Mr Inoue assaulted his daughter because she cried at night.
The same day, in neighbouring Saitama prefecture, a 44-year-old man dug a hole in the garden of the family home and buried his stepdaughter up to her neck. The girl, aged nine, was also slapped around the face and kicked.
The man, who has not been named, told police he was disciplining the girl because she would not do her homework and because she did not get out of bed on time.
Though a nation that has traditionally revered its children, Japan is facing an epidemic of abuse cases that experts warn is likely to get worse rather than better.
'There has clearly been an increase in incidents of physical, psychological and sexual abuse of children, as well as simple neglect,' says Jun Saimura, of the Child and Family Research Institute.
