Proof of Friendship

"Proof of Friendship" is an instrumental musical composition from the Japanese version of Yu-Gi-Oh! ZEXAL. It is the 20th listed track on Yu-Gi-Oh! ZEXAL Sound Duel 4, and is 2:40 long.

Appearances
"Proof of Friendship" was played in the following episodes:
 * when Yuma and Astral are about to perform a ZEXAL Morph, and become ZEXAL II.