Japanese euphemism for a gas chamber for unwanted domestic animals.
"Nearly 5,000 cats and dogs end up in this one regional pound every year. Of those, less than 300 find homes. Those that can't fend for themselves, like newborns, are disposed of immediately, while the rest sit on death row for seven days. They're then sent into here - the place they call the dream box - where they're gassed." - Singer pitches in to save Japan's condemned pets, abc.net.au, 27 Nov 2012.