Pressed by Naruto, Obito remembers the time he, Kakashi, and Rin teamed up for the Chunin Exam and when he promised Rin that he would become Hokage.
However, it's not compulsory.
ولكن الأمرُ ليسَ إلزامياً
Es ist jedoch nicht zwingend.
Sin embargo, el examen de 
chuunin no es una obligación.
Sin embargo, el examen de 
chuunin no es una obligación.
Però non è obbligatorio farlo.
Mas não é obrigatório.