Debute with Ohayashi ga kikoeru rear (お囃子が聞こえる日) in 1994.

From Wikipedia:

Igarashi is known among manga fans for his bold, detailed art style and innovative storytelling. While his works are often described as fantastical, they can hardly be categorized as traditional fantasy stories; instead, Igarashi draws inspiration from folklore and nature combined with surrealism and spiritual themes to create a style that has earned comparisons to the films of Hayao Miyazaki (Igarashi himself stated in an interview that Miyazaki's film My Neighbor Totoro was a key influence on his decision to become a manga artist).