On 22nd November 2010 Japan is struck by ten missiles, which incredibly
land only in uninhabited areas and claim no victims. An apparent
terrorist attack, the event is dubbed "Careless Monday" by the media and
is quickly disregarded by most of Japan's populace. Three months
later, Saki Morimi, a Japanese student visiting Washington DC as part of
a school graduation trip, is almost arrested during a misunderstanding
outside the White House but is rescued by a mysterious and completely
naked young man, Akira Takizawa, who shows up out of nowhere with no
memory and carrying a gun and a cell phone credited with 8.2 billion yen
to its account...
The two quickly strike up an unlikely friendship, that develops through the process of Akira working out who he is, and his ties with the Careless Monday attacks and the mysterious disappearance of 20,000 NEETs - young people, "Not in Employment, Education and Training", who vanished in the aftermatch of Careless Monday. That he has no memories never seems to worry Saki unduly - she comes across as a naive, trusting sort, who never seems to realise that the memories that Akira's missing could be of him committing untold violent crimes - 20,000 missing people is no small number, after all - and, to be honest, hormones seem to have struck both Akira and Saki: from the start they're quite clearly taken with each other, although whether their relationship moves on to something more formal is an issue the series steers well clear of.
Instead, it focusses primarily on Akira's quest to learn about his missing past. The phone he's carrying identifies him as a Selecao, and Juiz - the concierge he's able to contact at any time using his phone - is able to tell him that his memories were deliberately wiped through his own choice. After that - why he had the memory wipe, what the Selecao are and how they were chosen, who the other Selecao are - he's on his own. But since knowing what's going on is key to the story, let's let you into the secret: