Igarashi became exposed to the development of the Castlevania series when he began dating an employee at Konami who was working on Castlevania: Rondo of Blood and would later become his wife.   Igarashi was still relatively new to the video game industry and was working as the lead writer on Tokimeki Memorial, a dating simulation game for the PC Engine’s Super CD-ROM² System.  His girlfriend was giving him advise on how to write the story to Tokimeki Memorial and during his breaks he would play the game she was developing, Rondo of Blood.

Igarashi developed a passion for the series and informed his boss that he had no desire to work on a sequel to Tokimeki Memorial and requested to be transferred to join the Castlevania development team.  Igarashi’s involvement with the Castlevania series began in 1994 when he was assigned to a project to develop a Castelvania title for the Sega 32X.  Development began on the Castlevania title slated for the Sega 32X however Konami decided to scrap the game in mid 1995 in favor to develop a game for the Sony PlayStation.  Referred to as Castlevania: The Bloodletting though the game never received a firm approved name was cancelled however many of the initial ideas where incorporated into Symphony of the Night when the development team shifted from the 32X project to the PlayStation project.

Toru Hagihara led the project slated for the PlayStation while Igarashi was involved with the story-writing and programming.  During mid-production of the game Hagihara was promoted to the head of the division and asked Igarashi to finish the game as the assistant director.  From the beginning of the development the game was intended to represent a new direction for the franchise as linear games such as the previous installments of Castlevania offered very little replay value, something Konami was trying to address in order to keep their games out of bargain bins throughout Japan.  Igarashi felt that action games were too short, his goal was to create a game that could be enjoyed for a much longer period.

The development team was successful in their goal to create a new formula for the Castlevania franchise and even established a subgenre of action-adventure known as Metroidvania.  Symphony of the Night became a critical and financial success over time, establishing that there was a desire by players for Metroidvania style games.  Upon completion of Symphony of the Night he was assigned as the director of Elder Gate, a PlayStation RPG that released in 2000.  Igarashi had great ambition for the game wanting to create a game that could provide players with their own unique experience however the game fell short and received only mediocre reviews by critics.

Following the release of Elder Gate, he was assigned back to the Castlevania series, this time as the producer of Castlevania Chronicles, a PlayStation port of the 1993 Sharp X68000 game.  From that point forward Igarashi would continue working on the Castlevania franchise for the next 10 years before being reassigned to Konami’s Social division.  Over the course of the decade he produced and wrote Castlevania: Harmony of Dissonance, Castlevania: Aria of Sorrow, Castlevania: Lament of Innocence, Castlevania: Dawn of Sorrow, Castlevania: Curse of Darkness, Castlevania: Order of Shadows and Castlevania: The Dracula X Chronicles.  By 2010 Igarashi’s name became synonymous with Castlevania, however Konami’s corporate vision was shifting, and Igarashi would be reassigned to their Social division in 2011 to focus on more casual games.

From 2011 to 2014 he still produced a few console games such as the side-scrolling shooting game Otomedius Excellent for the Xbox 360, the Kinect game Leedmees and worked to localize the Nintendo DS game Scribblenauts.  At that point Konami’s business model continued to shift, this time towards mobile games.  Igarashi tried to develop mobile games that played more like console games but was unable to successfully complete any for release.  He felt that his experience with console games led him to be unable to make the leap to social games and ended up leaving Konami in March 2014.

Igarashi spent a few months looking for a publisher that would fund a new console game and after assessing his options decided to partner with Chinese businessman Feng Gang to found the company ArtPlay.   Igarashi met Gang while working on a potential mobile game at Konami that ended up being cancelled.  Both Igarashi and Gang recently left their respective companies looking for other opportunities.   Gang approached Igarashi to join him in founding a new company to create mobile games.  Igarashi initially refused as he did not want to work on mobile games however changed his mind when Gang proposed that the company would work on both mobile and console games.  The vision was to create mobile games that would create a profit to fund the development of console games, and the console games would spawn mobile spinoffs.

In September 2014, they founded ArtPlay an independent studio in Tokyo, Japan with a branch office in China that would focus on the development of mobile games.  Igarashi is the representative director of the company’s Japanese main branch which handles the creation of console games.  Inspired by Keji Inafune’s recent crowd sourcing project Mighty No. 9 he decided to launch his own Kickstarter campaign for his new project.  He created a pitch for the campaign by filming a promotional video for the new project as Castello di Amorosa in Northern California with the help of 2 Player Productions.