Sushi Sasa, which has been one of Denver’s favorite sushi restaurants for 20 years, said Monday that it has closed. Located at 2401 15th St., Sushi Sasa was owned by Wayne Conwell, who started it in 2005 after working at Sushi Den and for “Iron Chef” Masaharu Morimoto. “It has been an absolute pleasure and honor to lead Sushi Sasa for the past 20 incredible years.