The Tatami Room (和室 washitsu , lit. "Japanese-style room") is one of the areas Hiroshi has access to after having the first chase with the Oni. The basement key will be found in a jail cell located behind a hidden door . The lighter will be picked up here as well. Before you can get the lighter in Version 6, you have to run from the Oni that appears from the rightmost sliding door.
In Version 6.23, the tatami room was rearranged and the oshiire, Japanese-styled bedding closets, were removed.