He created the pachinko machine called the Bog. It was made in a way that it impossible for anyone to get the max payout unless he desires it to.
He first start his career by cleaning toilets at a casino owned by the Teiai Corporation. This is where he first meets Hyōdō who orders him to drink wine from a basin he dipped his feet in.
He eventually gets promoted to manager and becomes a subordinate of Yoshihiro Kurosaki. Along with his right-hand Murakami, he runs an illegal casino which holds his creation, the Bog.
Tobaku Hakairoku Kaiji
He is first introduced when Sakazaki attempts to beat the Bog. As Kaiji begins to observe and study the Bog from a distance, Ichijō is seen being warned by Yoshihiro about Kaiji which Ichijō brushes off.
For Kaijis plan to beat the Bog to succeed, he planned to plant a false reason to break the Bog by sneaking into the casino office. Here Ichijō catches him and uses a finger nail piercing device on Kaijis hand as warning for any future attempts.
Kaiji later returns with Sakazaki and Endou in his group where they start their final battle with the Bog. Despite eventually learning that the group must have been cheating to pass the barriers he has set up for the Bog to be unbeatable, Hyōdō calls in and forces Ichijō to continue with the gamble.
After a long battle, Kaiji eventually succeeds at beating the Bog. Hyōdō then demands that Ichijō pay back the ¥700 million Kaiji won by working for 1050 years in the labor camp. As Ichijō is dragged away, Kaiji encourages him to return and challenge him again.
He has yet to be seen nor be mentioned after the arc.
Chuukan Kanriroku Tonegawa
He is shown conversing and praising Tonegawa when he visits his casino to play the Bog.
Tonegawa comments himself on this as being treated like a child with the amount of work Ichijō was putting into his emotional outbursts while Tonegawa breezes through the Bog with ease (this is due to Ichijō secretly meddling with the Bog to make it easier for his superior to beat). Unbeknownst to Ichijō, Tonegawa already saw through this and didn't say anything.
Live Action Adaptation
- In Season 2, Episode 22, it was stated in an interview that Ichijō was created to be a moe character.