The jury has heard pages of text messages between Yu and his friend Yongxin Li in the days leading up to Kiko's death.
Yu has told the court that he regrets suggesting Kiko as a target for a planned robbery and murder.
Yu sent Li a text saying: "Kiko has probably quite a lot of money in the card. Family is also very rich. May consider it. Furthermore. I know her pin.''
He told the court he never had any intention of hurting Kiko and tried to talk Li out of the planned robbery and murder.
"He decided the target straight away and wanted to kill her.''
Yu said later text messages showed he did not want to go through with the murder.
In one of the messages, Yu told Li "I cannot harden my heart''.
He told the jury: "I didn't want to go ahead with it. I tried to get out of it. Furthermore, Kiko is my friend and I really didn't want to do it.''
Yu was also questioned about text messages sent between him and Li a week before the killing. In one of the messages, Yu told Li: "Oh ... I even have the thought of killing people ... Who do you find disagreeable? I will help you fix him.''
He told the court: "At the time I had a thought, I definitely needed the money so I was hesitating between mercy and the devil.''
Yongxin Li is serving a life sentence with a minimum non-parole period of 16 years for the murder of Kiko.
