Mafuyu's Younger Brother

Natsu Sato is the younger twin brother of our lovely boy Mafuyu. He's not really been mentioned in the band of Given. (this is story is orignal but it's set after the anime). Natsu has enjoyed music as long as he could remember and started a band that did mostly cover songs. (for the songs I will be useing the band Our Last Night). He and his three other high shcool friends make the band Metal Faires. What would happen if Natsu had been mentioned by Mafuyu whilst in band practice.