Faint

Takes place two years after in the manga.

Tsuna has grew mature. Due to a training session lasting two years around the world and then coming back to find all the paper work in the mansion of the Vongola HQ and that he has already been anounced as Vongola Decimo and is too long for a take back since Nono was long gone and settled in America.

But Tsuna's worries wouldn't end at just that. A earth quake and now he had to fix a problem in the past or he won't exist anymore!