In a bid to understand more about the novel ahead of the filming, Ayase went on a short trip for 4 days and 2 nights in order to meet Ishiguro who is based in London. During their discussion, Ishiguro explained that he wanted to explore the theme of life being very short and everyone will face death one day. However, how people deal with death in their faces and what they feel is most important to them was a key motivating factor which spurred him to write the novel. He also explained the relationships between the key characters and how he felt about the lead Kyoko (Kathy H. in the novel in response to questions from Ayase.
Ishiguro who moved to the UK at the age of 5, is a bestselling author who had won the Man Booker Prize which is the highest ranking literature award in the UK. As he didn't know about Ayase prior to their meeting, Ishiguro watched her 2009 drama "JIN" in order to know her better. After watching it, he praised Ayase for using her facial expressions and body language to convey the love which couldn't be put into words and commented that she is a great actress. In response, Ayase thanked him in English. As Ishiguro advised Ayase to play Kyoko in her own way rather than be restricted by the novel, she pledged to do her best to convey the essence of her character to the best of her ability.
Source: Sponichi Annex