Tadafumi Izuku is the husband of Kumiko Izuku and the driver for the hostesses of Club Eve.
Background
Tadafumi married his wife at 27 years old and supported her as a regular company employee. Three years into their marriage, however, he took up a second job as a driver for Club Eve to make up for his wife's lack of income. He began coming home late with more frequency, causing Kumiko to become worried about him and their tight finances.
Tadafumi and Kaori alone together
During his late-night drives, Tadafumi had fallen in love with Kaori, a hostess, and knowing that his wife would never agree to a divorce, the pair made plans to have her killed. When Kumiko began looking into his activities, he was unknowingly photographed leaving the hostess club with two women.
Synopsis
Niwaka Samurai Impersonator Arc
Kumiko brings evidence of her husband's activities, including hostess' business cards and photographs, to the Banba Detective Office. Xianming Lin decides Tadafumi is guilty out of prejudice against Kumiko, but Zenji Banba has his doubts and agrees to investigate her husband's affair, sending Lin to infiltrate Club Eve. At the club, Lin discovers that Tadafumi has taken on a part-time job driving the hostesses home after their shifts.
Abe checks Tadafumi's ID
In another part of Nakasu that night, Genzo Gohda tasks Abe and Yamamoto with assassinating one of his former killers, a man who had killed the wrong target and is blackmailing Genzo for money. The pair splits up to find the man wearing a blue shirt, and Yamamoto follows him into a parking garage and stabs him. Arriving on the scene, Abe discovers the man is not their intended target, but Tadafumi Izuku.
Lin relates Tadafumi's innocence to Kumiko, who insists that he must be having an affair and asks him to look for her now-missing husband. Lin accepts the task and passes it along to Enokida, who learns from the daily news that Tadafumi's body has been discovered in Hakata Bay and identified.
Kaori, a hostess from Club Eve, approaches Jiro Tanaka with a request. She reveals that she and Tadafumi had fallen in love and been having an affair, and they had planned to combine their savings to have Kumiko assassinated. She gives their savings to Jiro, asking him to take revenge on Tadafumi's killer.