When he joined Sega in 1992, Iizuka assisted in debugging Sonic the Hedgehog 2 as part of his job training.

Iizuka agreed and relocated to the United States to work on the game's level design.

In 2016, Iizuka relocated to Los Angeles to become the VP of Product Development at Sega of America, while retaining his title as the head of Sonic Team.

[4] In 2022, it was revealed that Iizuka designed a game named Devi & Pii for the Sega Genesis in 1992, but it was never released.

[6] His long time colleague and composer, Tomoko Sasaki, however described him as someone who "offered a different and fresh, almost unpredictable, way of thinking" and got along well with him from the very start.