Original: It is said that one day, he saw a wild boar and proclaimed, "I want to kill Soga Umako like this wild boar." This angered Soga no Umako and, perhaps out of fear of being struck first, Umako had Sushun assassinated by Yamato no Aya no Ataikoma in 592.
Simplified: The emperor's first minister was his powerful uncle, Soga no Umako.