Included on this page are official proficiency badges given to soldiers who have completed
various course of study and skills tests. I don't have a picture of every variety of badge, so I
welcome any help!
The best (only?) resource for these badges is
Orders and Medals of Japan and Associated
States
by James Peterson (get the third edition). However, Peterson doesn't mention the dates
when the badges were established nor does he note the different classes (if any). I'll try and fill
in those gaps here as best as I can.

And even in Peterson's book, not all the badges are listed.

More badges are on these pages:
Army Proficiency Badges page 2
Army Proficiency Badges page 3
Model 1887 Shooting Badges. See below, too.
Note the differences in the coloring and stamen size, for example.
Army Proficiency Badges
陸軍徽章
Some reverses. Note the wide pinback. A thin, sharp pin most likely
indicates a replica. However, some better replicas have the
appropriate reverse.
Swordsmanship Badges
Established Showa 9 [1934].
Differences in color probably indicate the class, and differences in material indicate age.
The aluminum badges are most likely late war manufacture.
Shooting Badge
Established Showa 4 [1929].
'NCO badge.'
'2nd Class badge.'
The most commonly seen Army Proficiency badge is certainly the Sharpshooting
badge. It is called by a variety of names, such as marksman badge, sniper
badge, shooting badge as well as others.
The Japanese name suggests that 'Shooting badge' may be the most literal
translation, but anyway proficiency shooting firearms is the main idea. The full
Japanese title reads 'Infantry and Engineer, Shooting Drill Badge.'

From what I have heard, this award has gone through a number of different
changes. I will list what I have read, but the information is secondary so I haven't
confirmed it.

1882: No badge. Just a chevron on the right sleeve
1886: A round medal w crossed rifles instituted
1887: The chevron was discontinued
1888: A pin-back version with crossed rifles on cherry blossom begins. This is
the widely-known design.
There were design changes in 1895, 1912, 1929, and 1941.
Before 1912 the class was engraved on the reverse, but later this was only
indicated on the box. And of course the color scheme indicated the class.
The 1929 version has a thicker, sturdier blossom with a pebbled texture.
The 1941 version was aluminum.

As you can see by the illustrations found in Japanese Army publications, there
were four classes.

By these pictures, we can know the color schemes:

1st Class: Gold rifles and blossom, silver trim.
2nd Class: Silver rifles and blossom, gold trim.
3rd Class: Bronze rifles and blossom, gold trim.
4th Class: Bronze rifles and blossom, silver trim.

I am not sure exactly what the standards were for each class.
From a 1918 Japanese Army handbook.
From a 1912 Japanese Army handbook.
Picture from a 1912 Japanese Army Field Artillery Textbook
TOP: 'Fortress Artillery Observer Badge.'
BOTTOM: 'Fortress Artillery Signaller Badge.'
Picture from a 1918 Japanese Army Draft Preparation handbook
RIGHT: 'Fortress Artillery Observer Badge.'
LEFT: 'Fortress Artillery Signaller Badge.'
Fortress Artillery Observation Badge.
Field Artillery Observers Badge with original case.
The English translation of the name of this badge appears to be
slightly wrong. A more accurate (but perhaps less smooth) rendering
would be 'Field Artillery Gun Sight Badge.'
Picture from a 1912 Japanese Army Field Artillery
Textbook
TOP: 'Field Artillery Gun Sight Badge.'
BOTTOM: 'Fortress Artillery Gun Sight Badge.'
Picture from a 1918 Japanese Army handbook
RIGHT: 'Field Artillery Gun Sight Badge.'
LEFT: 'Fortress Artillery Gun Sight Badge.'
'Field Artillery Rapid Firing Badge.'
These resemble the badge above, but there are differences in the
cannon bases and tips.
Contrast this badge with the ones above. The
cannons are plain. This is the 'Light Mortar
[
keihaku in Japanese] Gun Sight Badge.'

Peterson names this a 'Light Mortar Badge'
but the Japanese source named this as a
light morter gun sight award (not a firing
award).
Army Proficiency Sharpshooting Badge award document. Given to
Army Infantry Private 1st Class Sakamoto Haruyoshi by the 24th
Regiment, 4th Company. The document is dated Taisho 6 [1917]
October 28.
Peterson identifies this as the Model 1895 Heavy Artillery Observer Badge, though his line drawing is upside-down
(pg. 105). He describes it as having a pebbled background, so this one may be a later model.