"Iryu Sousa" began as a drama series in Spring 2011 and has 3 full-length series and 4 SPs to date. Kamikawa plays the lead character Itomura Satoshi, a police detective who depends on the items left behind in crime scenes to obtain clues in solving cases. Besides Kamikawa, Koumoto is the only actor who has appeared since the first season as the police detective Muraki Shigeru assigned to Kyoto Prefectural Police's forensics department coincidentally at the same time as Itomura who is transferred to Kyoto too. Kamikawa remarked that he was glad for Koumoto to join him in Kyoto as without him around, a signature trait of the series i.e. the conflict between Itomura and Koumoto will be lost.
The cast were also asked to write their wishes for Tanabata where Kamikawa asked for the right amount of heat and rainfall. As the filming is done mainly in Kyoto where it can get really hot in summer, it will be nice to have fine weather without too much heat so that filming can progress smoothly. However, if there is no rain, it will be bad for those in the agricultural industry so that's why he added the part asking for the right amount of rainfall in his wish. On the other hand, Koumoto wrote "No Cut Muraki" which means that he doesn't want any of his scenes in the drama to be cut. As for Toda, she hoped that she could memorise the lines in the script quickly while Danta hoped for a good performance from his favourite baseball player Uemoto Hiroki in the Hanshin Tigers team.