Police arrested a 24-year-old man for allegedly stabbing a man to death and injuring his three children after breaking into their home early Wednesday in Osaka Prefecture.

Yuma Kobayashi, who is attending part-time high school, is suspected of killing Yukinobu Kawakami, 43, who was sleeping on the second floor. Kawakami was rushed to a hospital and pronounced dead.

Kobayashi has denied the charge and says he does not clearly remember what happened, according to police. When arrested at the scene, police found him holding a knife.

Kawakami's eldest daughter, age 19, who was injured in the attack, alerted police at around 4:10 a.m. Her younger sister, 17, and 15-year-old brother also sustained injuries. A 1-year-old baby, the eldest daughter's child, was unharmed.