The 14-year-old boy arrested Saturday on suspicion of fatally stabbing a 57-year-old neighbor had been responding to counseling and appeared to have adjusted to school life, counselors said Sunday.

The boy, whose name is withheld under the Juvenile Law because he is a minor, was arrested for allegedly stabbing Kazuhiro Sugiyama in the corridor of their apartment building in Shimizu, Shizuoka Prefecture.

According to investigators, Sugiyama would often visit the boy's home in the dead of night in a drunken state and argue with his father. On Saturday morning, Sugiyama and the boy's father had had a quarrel, and it appears the boy, who was very close to his father, attacked the neighbor in an effort to help him, sources close to the investigation said.

The boy has admitted to the act and has said he is sorry for what he has done, police said.

On Sunday, counselors assigned to the boy said that in May the youth often stayed home from school and rarely spoke with them. However, in recent weeks there were signs that he was getting used to school life, and that he could be seen playing table tennis with schoolmates.

"The boy had started going to school regularly, and we were all pleased. I can't believe that he would do such a thing," one counselor said.

According to school officials, the boy enrolled in his current junior high school in February after leaving a facility in Hamamatsu, Shizuoka Prefecture, that helps children requiring special attention.

Because he had difficulty adapting to the new environment, he began attending counseling sessions.

He began attending school more frequently from September and had been gradually showing interest in catching up in his studies as well, counselors said.