Nakayama went through an audition in May this year and got the offer after the scriptwriter and director Takimoto Tomoyuki and staff decided that he was the best person to play Hokuto. Filming began on 16 August. In order to show the desperation of Hokuto who was prepared to give up his life while behind bars and awaiting trial, Nakayama went on a strict diet since mid September when the court scenes were shot and had already lost 12kg to weigh only 40+ kg by the time the filming concluded on 2 October.
Nakayama recounted that when he went for the audition, he remembered clearly how much he was in awe by the lines he had to read and was worried whether he could handle this role when he got the script. As such, he was shivering with excitement when he got the chance to act in this drama and called upon the viewers to watch this drama which has some scenes that they may find it difficult to stomach.
Sources: Sanspo / Yomiuri Hochi / Sponichi / Eiga.com