Here area few items related to the Showa Emperor Enthronement Commemorative Medal.
The first is the presentation certificate.
Showa Enthronement
Commemorative Medal
page 2
Top center
Bottom center
Corner design
Here are two paper items associated with the 1928 Showa Enthronement Medal. The
smaller item is the paper wrap and can be found fairly easily. The larger document is
from the Awards and Medals Department and reads

"On the obverse of the Emperor Enthronement medal is the word 'Banzai' and on the
reverse is 'Emperor Enthronement Medal, Showa 3, November.' These are written in the
hand of
Prince Kan'in Kotohito, Official Head of the Imperial Attendants."

This man was also Hirohito's great-uncle, having been adopted by Emperor Meiji's father.
Unofficial badge? Perhaps an attendant's
badge? The badge is not high quality.
I think this is an official's sash for the 1928 Showa
Emperor Enthronement celebrations. The sash has the
same colors as
the official medal. There are two red
tassels attached, and a metal cherry blossom. This is
long, about 80 cm, so it would easily fit over a shoulder.
There is no attachment device, though. It appears to have
been cut off.
Unknown maker.
Inscribed 'Imperial Enthronement
Commemorative Badge, Showa 3 [1928]
November.'
Gold medal. There is also silver version of this. Hallmarked by the Japanese Mint.
Inscribed 'Gold prize, Imperial Enthronement Commemorative Exhibition, Tokyo, Showa 3
[1928] November.'
Inscribed 'Imperial Enthronement Celebration,
Patriotic Youth Brigade, Officer's Commemorative,
Showa 3 [1928] November 20, Mie Prefecture.'
Inscribed 'Emperor Enthronement Commemorative, Domestic
Industries Tokyo Exhibition, Showa 3 [1928].'
'Imperial Culture Association Emperor Enthronement Celebration
Commemorative. Showa 3 [1928] November 10.'
'Banzai' is written on the obverse banner.
'Imperial Sericulture Association Emperor Enthronement Commemorative.
Showa 3 [1928].'
The inscription reads 'Imperial Enthronement Viewing Commemorative, Tokyo City Federated Patriotic Youth
Brigade, Showa 3 [1928] December 15.'
1928 Showa Enthronement commemorative Cavalry badge?