Ichirou Shidou (獅童 一郎, Shidō Ichirō) is Koichi Shido's father and a corrupt politician.
Little is known about Ichirou except that he was a debater in the Diet, and he was a candidate for Cabinet Minister. While it is unknown whether he won the election for Minister, he is seen to have a great amount of power and influence later when his son, Koichi Shidou, becomes an adult. Ichirou seems to fit the typical profile of a corrupt politician in that he uses illegitimate sources to acquire funding, he is adulterous, and he manipulates people who threaten to expose him into backing off. He also has some affiliation with Souichiro Takagi.
Ichirou's exact appearance is unknown as he has never been seen clearly. However, it can be determined that he is a bit overweight, is mostly bald, and wears glasses.
When Koichi was a young child, Ichirou was a Diet debater. He ran for Cabinet Minister while Koichi was still a child. During this time, Ichirou had at least one mistress that his wife knew about. Other than this infidelity, there is no evidence to suggest Ichirou became corrupt until around the time his wife died and Koichi was in college.
Ichirou is shown as being ruthless and power-hungry. He will do whatever it takes to protect his image and maintain his position. This is shown when he has Rei Miyamoto held back a year in school to threaten her father into not exposing him. He does not seem to care much about his wife since he commited adultery on her, and he even had an illegitimate child with his mistress. He did cry at his wifes funeral, however, it is unknown whether this was genuine sadness or merely a facade to uphold his public image. He also doesn't seem to care about Koichi, as he named his illegitimate son his heir instead of Koichi.
Ichirou's current fate as of the current storyline is unknown.