The former head of a nationwide chain of day-care facilities pleaded guilty Tuesday to professional negligence resulting in the March death of a 4-month-old boy. The infant suffocated after an older baby rolled on top of him while they were in the same bed.

During the first hearing before the Tokyo District Court, Masamitsu Maekawa, 53, former president of Toyama-based nursery operator Chibikko-En, admitted he had failed to take adequate measures to ensure the safety of toddlers entrusted to the center's care, having put the business' profits first.

Standing trial on the same charge is 37-year-old Kozue Maedomari, a director at the firm, which changed its name to Maxcom in September.