[3][4][5] His parents house was an art supply store, and his grandfather was a painter.

[6] Shirai's brother, who had been watching anime since he was young, went to Tokyo to enter vocational school to become a voice actor.

Due to that, Shirai decided to become a voice actor and entered vocational school himself.

[7][5] After graduating from vocational school, he entered a narrator training center, but later left.

[7] However, he left the school after one year and entered the Amusement Media Academy.