A 15-year-old boy has pleaded guilty at Sheffield Crown Court to the manslaughter of teenager Harvey Willgoose, but has denied his murder.
Harvey was stabbed to death at All Saints Catholic High School in Sheffield in February.
The defendant, who cannot be named because of his age, admitted manslaughter but denied murder. He also pleaded guilty to having a blade on school premises.
A murder trial date was set for 30 June and the boy was remanded into youth detention custody.
Harvey was stabbed twice in the chest while on a lunch break at the school.
His funeral at Sheffield Cathedral was attended by hundreds of people, with the service shown on a big screen to a crowd outside.
In a statement issued after his death, Harvey's family said they were "utterly heartbroken".
"Our lives are devastated and will never be the same again," they said.
"We have lost a beloved son, brother, grandson, cousin, nephew and most importantly, a best friend to all.
"Harvey will be forever known for being a caring, loving and funny young man."
The school's head teacher described Harvey as an "immensely popular" young man whose "smile would light up the room".
Harvey’s parents have become anti-knife campaigners, calling for knife arches to be installed at secondary schools.
