Two teenagers face a total of 16 years in prison for an attack of “nauseating brutality” on an Oxford student.

Craig Knowles and Thomas Mack were jailed on Friday for assaulting Kentaro Ikeda, a postgrad student at St Edmund’s Hall, as he cycled home through University Parks in July last year.

The youths, both 18, dragged Ikeda from his bike before striking him on the head with a metal bicycle lock, Oxford Crown Court heard. They fled with his laptop, mobile phone, rucksack and bike, leaving the victim semi-conscious and bleeding.

Ikeda was found by passers-by, and rushed to the John Radcliffe Hospital for emergency surgery. The attack has left him semi-paralysed and with serious brain damage.

Knowles was jailed for 9 years after he confessed to causing actual bodily harm, grievous bodily harm with intent, and robbery. Mack denied all charges and faces 7 years in prison.

Ikeda now resides in a rehabilitative centre near Tokyo, where he receives permanent care. He spends his days in a wheelchair and is only able to type on a computer with one hand.

During the trial, Ikeda communicated with the jury via recorded interviews from his hospital bed. He told the court, “this attack has left me partly paralysed on my left side. I have no movement from my left elbow to the fingertips. This makes is very difficult to perform everyday actions. I have difficulty in concentrating.”

However he added, “I remain optimistic for the future and one day I would like to resume my studies.”

Judge Terence Maher told the court, “this man’s life has effectively been stolen from him.”

“It is no exaggeration to say this is an offence of the utmost gravity which has had life-changing consequences for the victim. All this from a few moments of nauseating brutality.”

The Judge described the attackers as “exalting” in the crime, shown in text messages they sent to friends shortly after the attack.

These messages allegedly included the phrase, “mate, you missed out… we saw a Chinese man on the way back and beat the shit out of him,” and, “that’s how Marston boys roll.”

Detective Chief Inspector George Bain, who led the investigation, commented, “the drunken behaviour of these two men has left the life of a promising academic changed forever.”

Friends of the victim expressed satisfaction that the case has been resolved, but concern at the length of his attackers’ sentences.

Evan Innis, also a postgrad at Teddy Hall, said, “on the one hand, I am happy that the case has been resolved, but on the other hand, the sentence itself is too light, as it seems that they could have intentionally killed him… The verdict feels very light.”

Chernein Oon, a student at Merton, added, “9 years of imprisonment for a life that might never be the same again… Not quite fair, but at least justice has been served.”

Mrs Ikeda, the victim’s mother, said, “Kentaro would like to thank everyone for their help in his case. He feels that both his attackers should be given appropriate sentences as his life has been very much changed due to this incident.”

The incident has had irreversible consequences for Ikeda’s family, who had relied upon the money invested in his education to provide for their future. Ikeda’s father died several years ago. After the attack, his mother had to take early retirement to become his full-time carer.

A friend of Ikeda from Merton College said that he is recovering, but that it is still unknown whether he will return to Oxford.