Nagayama Kento will be playing the role of 31-year-old Takagi Shinjiro who is an ambitious and arrogant sergeant and adopts a negative attitude towards being told to investigate unresolved cases right after he gets transferred to the department. While working with Ishikawa Yuri (Yoshida), he starts to change his mindset. Nagayama commented that he was feeling quite assured that things will work out well when he found out who his co-stars were. Although the five of them are very different, there is a lot of chemistry among them and he finds it interesting to act with his co-stars. In addition, as he is also the youngest child in the family like Yoshida, the two of them get along very well so they were able to show the chemistry as a pair of buddies working together.
Takito Kenichi plays the role of Tachikawa Daisuke, a lieutenant who is Yuri's colleague and has a frank character but short temper. He is living apart from his wife who has had enough of him. Takito commented that everything about this drama including the staff, cast and script is very good but he can't really see anything charming about his character. However, while filming the drama, he developed a liking for his character and hopes that viewers will like Tachikawa as well.
Mitsuishi Ken plays the role of Kaneko Toru, a lieutenant who had worked for many years at a police post so is very familiar with the local area. He is calm and makes use of his extensive experience to support the team and is nicknamed Neko-san. Mitsuishi revealed that his character is an only child who was actually headed on the wrong path once which coincided with his personal experience so he tried to tap on that to play his character.
Last but not least, the boss of Yuri's team i.e. Motoki Hidetoshi is played by Miura Tomokazu who is an inspector standing in for the section chief so everyone calls him "Dairi". Although he is a strict man, he cares for his subordinates. Miura commented that as the original drama series in the US lasted for 7 seasons, he thinks that it is a very good and popular drama. As such, he hopes that the Japan version will do as well and called upon viewers to support their hard work.