9 episodes.

1. According to the query of the "Volleyball Boys" novel: Miyaji made his debut in the volleyball club match of Shiratorizawa Academy High School in Chapter 9 of the manga.

2. Comic Chapter 18: Gong Yoo made his debut in the county qualifiers.

3. Chapters 27 to 29 of the comic: Gong Zhi and Gong Yu participated in the national competition.

4. Chapters 36 to 39 of the manga: The match between the Miya twin brothers and Karasuno Academy is the most exciting one. Gong Yu’s super high school level assistant and Miyaji’s super high school level decoy are the first time Join forces to fight.

5. Chapters 55 to 57 of the comic: He also performed well in the competition with the powerful schools in Tokyo.

6. Chapters 104 to 106 of the manga: Gong Yu showed his strength as Hinata Shoyo's opponent in the national competition.

7. Chapters 146 to 149 of the comic: In the first battle with the Brazilian powerhouse Valliega, Miyaji showed his strength.