He said Yu actively encouraged and helped Li carry out the killing. Yu has told the court that he and Yongxin Li took Kiko out for a driving lesson but he had no idea that his friend would kill Kiko.
Mr Perkins said the motive for the killing was money but there was also an element of killing for "killing's sake''.
He pointed to a text sent from Yu to Yongxin Li a week before the murder that said: "Oh... I even have the thought of killing people... Who do you find disagreeable? I will help you fix him.''
Mr Perkins said it was that text that got "the ball rolling''.
He referred to the plan to murder Kiko as the "metaphorical train''.
"Not only was he on this metaphorical train, he was driving.''
He said Yu and Li were "incompetent'' in their planning of the murder. They left bloodied items of clothing at home, allowed themselves to be filmed on CCTV cameras buying the knife at a supermarket and organised the crime using text messages.
"But trumping all of that is the fact they didn't check her pin number or confirm it. She died for absolutely nothing.''
Defence counsel Mark Edgar said his client had suggested Kiko as a target but he immediately tried to put his friend off carrying out the attack.
He referred to text messages between Yu and Yongxin Li, one of which said: "F*** This is not very good, is it? I kind of can't harden my heart...''
Another text said: "Think this way. For this little amount of money, she loses her life. Really not worth it, is it ... wait and see''.
He said Yu was having problems with his girlfriend at the time and had sent a number of texts to her and his friends asking for advice.
"It affected his thoughts and feelings and even his peripheral judgement.''
Mr Edgar also questioned the Crown's motive of money being behind the killing. He pointed out that Li paid a friend $1000 to drive Kiko's car with her body in the boot to Hamilton more than a week after the killing.
"He's a young man. He's made some foolish decisions as he has told you in the witness box. But there's a difference between foolish unwise decisions and being consigned to a murderous plan.''
Justice Kit Toogood will sum up the case to the jury of five women and seven men tomorrow morning before they retire to consider their verdict.