Full Moon, Vol. 2, Chapter 6
The Under-age Speech Contest
This is a reference to a speech contest held on public television called the “Coming-of-Age Speech Contest.” This was a contest where people who’d come of age (= age 20) would give speeches on various topics. The contest used to be held on “Coming-of-Age day,” a national holiday. (The holiday used to be Jan. 15, now it’s the second Monday of January.)
Shibuya Location
The building Madoka’s commercial is shown seems to be the QFRONT building. It’s a building with a big display on its side.
Denny’s
Yes, there are Denny’s in Japan. If you go to the suburbs, there are quite a number of them around.