Reborn enters into the Sawadas' household, but doesn't realize that what was Iemitsu's little boy is now his young daughter.

Tsuna doesn't know how he dies for good, only that he still has regrets when he does. When he wakes up, he's in the body of Sawada Nana, mother of a 2 year old Tsuna, and those regrets become tenfold. He's drowning in the implications, when an Arcobaleno appears on his doorstep, and the future becomes infinite possibility.