'I'm Not His Replacement' (OC X TQQ Fanfic)

What would've happened if Fuutaro passed away? What if he never managed to meet the one he met once more? These are the questions that would be very tragic.

Though, in this tragic world without Fuutaro, he does have a twin. A non-identical twin. Going by the name Azu Uesugi, he was delinquent following his father's path. After the tragic death of Fuutaro Uesugi, Azu had vowed to be a better brother and carry on his name. He changed himself for the better and became the person Fuutaro strived to be for him. And just like the story went... He had met the quints.