Police arrested a married couple in Tokyo on Wednesday on suspicion of leaving the mother's 5-year-old daughter unattended and without sufficient food or medical care, resulting in her death.

According to the police, Yudai Funato, 33, and his wife Yuri, 25, physically abused the girl named Yua from late January and failed to provide her with sufficient nourishment. The neglect resulted in her death on March 2 from sepsis caused by pneumonia.

Yua weighed only 12 kilograms when she died, compared with the average weight of 20 kg for girls her age. Funato is not the girl's biological father.

The police believe the couple effectively abandoned Yua because they were afraid the abuse would be discovered. In the end, Funato made an emergency call, saying "Our daughter has not eaten for a few days and vomited, and her heart doesn't seem to be beating."

The police found a notebook and memos written by Yua at their home that were filled with pleas to her mother and stepfather to stop abusing her.

The family had lived in Kagawa Prefecture, where Yua was taken into temporary protective custody twice by a local child welfare center, before moving to Tokyo. The Kagawa Prefectural Police had referred Funato to prosecutors twice on suspicion of injuring the child.

He had been arrested earlier and indicted for injuring Yua by punching in the face at their home around the end of February.