Medals of Honor
There are a variety of ribbon colors to the Medals of Honor , and the difference in color denotes the type of medal. Each
medal has a bar that has the date of issue. Upon the 2nd and subsequent awards, no new medal is issued. Rather, a new
bar is added. I have seen multiple bars on the Dark Navy Ribbon medal (issued for monetary contributions), but it is rarer to
see them on the other medals.
The 1887 Yellow Ribbon Medal of Honor is included in this group, but it is often excluded
because of its ribbon shape and the design of the medal, which is quite different.

Note that all of the medals have the recipient's name engraved on the reverse except for the Dark Navy Ribbon Medal of
Honor. These have plain reverses. This difference may be because the Dark Navy Ribbon medals were given when money
was donated while the other medals were given for merit of deeds or service.  Ribbon bars, bow rosettes, and button
rosettes can be found for most of these, depending on the date of issue.

In 2003 a renovation of the design of these medals was instituted. You can see the new design on the official
Japan Mint
page. There are two bars shown here, a silver and a gold one. I am not sure if they are engraved with the date.

PRE-2003 CRITERIA (see page 2 for the post-2003 criteria)
RED RIBBON MEDAL OF HONOR: Instituted in Meiji 14 [1881]
Saving a life
GREEN RIBBON MEDAL OF HONOR: Instituted in Meiji 14 [1881]
Merit in morals
BLUE RIBBON MEDAL OF HONOR: Instituted in Meiji 14 [1881]
Public service, either through donations or actions
DARK NAVY RIBBON MEDAL OF HONOR: Instituted in Taisho 7 [1918]
Public donation (5,000,000 yen minimum in 1988--no doubt more now)
YELLOW RIBBON MEDAL OF HONOR: Instituted in Showa 30 [1955]
Diligence in public work
PURPLE RIBBON MEDAL OF HONOR: Instituted in Showa 30 [1955]
Merit in arts and letters

The rarest are the Red and Green, followed by the Purple (see chart below for actual figures). The Japan Award Department
keeps a record of all the recipients and has published annual  rolls in beautiful volumes (see
HERE for an example).

Here are some of the various awards.
Yellow Ribbon Medal of Honor . Awarded for diligence in public work
The suspension bar has the date of the award: Showa 39 [1964] May 16.
The reverse has the name of the recipient: Gift to Hatano Katsuhiro.
Pure silver Blue Ribbon Medal of Honor with case and bow pin rosette.
Dated Showa 31 [1956] November 3 on the bar. Only 533 were awarded that year.

Awarded to a man named Yamasaki Ryousaku.
Red Ribbon Medal of Honor. Awarded for risking one's life to save another.
The suspension bar has the date of the award: Meiji 17 [1884] October 21.
The reverse has the name of the recipient: Gift to Englishman W. Muir.
Green Ribbon Medal of Honor.
Dated Showa 15 [1940] November 10 on the bar.

Awarded to a man named Kosaki Isao. His decoration rank (
Kun 6 tou) is also engraved on the
reverse, which I have never seen done before.
According to my 1941 medal rolls, he received this medal for performing a variety of services that
contributed to the public good. Specifically, he was cited for these 3 things:
1. Helping merge 3 smaller banks into the Hokubu Bank .
2. Being head of the sake [rice wine] manufacturing federation of Fukuoka and of Kyushu and
developing that body.
3. Being one of the main developers of Unoshima Rail Line.

Mr Kosaki lived from 1864 to 1953, and the
Buzen City website has a page devoted to him (in
Japanese, of course). It shows a bust of Mr. Kosaki that is located somewhere in the city.
Purple Ribbon
Here is an additional  bar for a Medal of Honor .
Upon receiving subsequent Medals of Honor of the same color, the
recipient was not given additional medals; he was given an extra bar
to attach to the medal he already owned. In this case, the bar was
presented in this pressed cardboard box. The inscription on the lid
reads 'Merit Medal Decorative Bar.'

The bar itself has the date of the award engraved: Showa 56 [1981]
October 31.

It is not possible to tell the color of the Medal of Honor by just the bar
alone, so this could have been for any of the medals. However, odds
are it was for the Dark Blue Ribbon Medal of Honor .
Rare Dark Blue Ribbon Medal of Honor with gold bar (indicating 5 awards) and an engraved
reverse. Although the 1927 ordinance specified that this medal would not have an engraved
reverse even with the gold bar, perhaps there was a post-war ordinance that I am unaware of.
Anyway, the person who owned this medal was given the award six times. The original date on
the decorative bar reads 'Heisei 2 [1990] February 24.' The five dates on the reverse are:
Heisei 2 [1990] August 29
Heisei 3 [1991] February 27
Heisei 3 [1991] May 29
Heisei 3 [1991] September 28
Heisei 3 [1991] October 30
'LH' on reverse of gold bar
'D8' on reverse of silver bar
Dark Blue Ribbon Medal of Honor with two decorative bars. the
main one is dated Showa 50 [1975] April 26, and the small one
Heisei 3 [1991] October 30.
There is also a modern medal bar. These were offered for sale
privately and were not awarded with the medal.
Left: Interior of a 1940 case.
Right: Interior of a 1963 case.
Dark Blue Ribbon Medal of Honor. No name on reverse, as is proper.
Dated Showa 38 [1963] August 31 on the bar.
1999 case
Yellow Ribbon Medal of Honor award document. This is award number 291.

Awarded to Hori Jouji. Dated Showa 30 [1955] November 3. This is the first year
of the Yellow Ribbon Medals of Honor, so this is one of the very first awards.

The document explains that Mr. Hori received the medal for many years of
work developing high voltage electricity conduction. After a quick online
search, I found that Mr. Hori had written a number of books and articles about
towers for high voltage cables. The earliest I found was published in 1941, but
there may have been more. He was born in 1900 and died in 1993.