Rather typical Tokyo main fire station, with a ladder, command vehicle, two pumpers, a foam pumper (or possibly a rescue truck?) and an ambulance. The watch for a station like this is normally around 25 members.
Note the absence of appliance room doors - although not universal, I have seen a lot of fire sations in Japan which have no doors, because there is simply no concern about theft or vandalism.
When I was stationed in Japan, I don't remember any career station having appliance doors. Not even out in the countryside. But, I would find large regional stations, that would be similiarly equipped as the Tokyo station above.
Now, all the volunteer stations would have red appliance doors, usually pull down shutters. The one exception was a 7 stall volunteer station in south Kyushu. All each stall had was a chain draped across the doorway.
There are doors, closed during the night. You are right about your comments, 90% of Japan's FS are open during daytime, just with a chain line or net. As for the above picture the 3rd pumper was a reserve stationed for the Tokyo Marathon event, normally there is a salvage crane vehicle instead.
Added by Jacques PETER on 28 July 2013.
For some reason all of the full-time stations I saw in Kyoto had glass doors, just as in the US and other countries, but many in Tokyo and other cities were wide open. But I did not visit any after dark - too many other interesting things to do!
Summer visitors to older east coast US cities like Baltimore, Boston and New York will often find fire stations' doors open. This is because so many of them are more than 100 years old and either have no airconditioning or very marginal window type systems - so a big wide open apparatus door or two help a lot with ventilation. It also provides the younger members with an opportunity to observe the more interesting passing pedesrians and exchnge a little harmless banter!
Note the absence of appliance room doors - although not universal, I have seen a lot of fire sations in Japan which have no doors, because there is simply no concern about theft or vandalism.
Added by Rob Johnson on 26 July 2013.