Teachers and friends have paid tribute to Kodjo Yenga, the 16-year-old stabbed to death on Wednesday in west London.
Kodjo was stabbed through the heart
Paul O'Shea, principal of St Charles Catholic Sixth Form College where Kodjo was a student, called him "a friendly, gentle and peaceful young man".
Messages posted on Kodjo's personal webpage said that he would be "dearly missed" and would "never be forgotten".
Seven people, aged 13 to 21, have been arrested and are being questioned at separate west London police stations.
Kodjo, of Portland Road, Notting Hill, was stabbed in the heart during an attack in Hammersmith Grove on Wednesday evening.
Flowers and candles have been left at a makeshift shrine near the row of shops where he was stabbed.
According to Mr O'Shea, Kodjo was "an able student... who was regarded with great affection by his fellow students and his teachers".
"He was a credit to his mother and wider family, to whom all the students and staff at St Charles College offer their heart-felt condolences."
Those sentiments have been echoed by users of the Bebo website, on which Kodjo had a webpage under the nickname Kizzle Sweet-thug.
"I love u bruva," reads one posting, while another describes him as a "fallen soulja" who was "loved dearly".
Police said the area was busy at the time of the stabbing and have appealed for witnesses to come forward.
Det Ch Insp Tony Nash said: "We know there would have been a lot of people in the area at the time of the murder and I would urge anyone who saw what happened, or who has any other information about those responsible, to come forward to police."
One eyewitness described seeing the teenager being chased by a gang who were throwing sticks and shouting.
Another resident said she heard that the gang had been hitting the windows of a local shop before chasing the victim up the street.
Local MP Greg Hands said he was "very upset at this appalling murder".
"This was a horrific attack in daylight in a relatively busy street and will send shock waves through the community. My sympathy goes out to the family of the victim."
Four 13-year-old boys are among those being questioned.