The father of a 45-year-old woman severely injured in Tuesday's deadly knife attack at a care facility for people with disabilities has described his deep anger and anguish over the incident.

"We've experienced many tough times, but we adore our child regardless of whether she has disabilities or not," said Nobuyuki Noguchi, 76, while looking at a photo of Takako Noguchi, his daughter who is unable to speak.

"It must have been especially tough for her since she can't express her pain in words. I feel like my blood is boiling with anger," said the father, who says he can understand her thoughts through her facial expressions and behavior.