Voices Fading in the Waves (2015)

A lady,YURIKO, gets on a Taxi in the middle of the city of TOKYO and tells a driver,REN, to just keep on driving, without telling a destination. As she pays a huge amount of money in advance, Ren decides to obey her order, however, he finds a bloodstained bill in it. What does that blood have to do with it? What is Yuriko running away from?