>>Is it possible for a person to receive this honor twice? > >I think it was like the Knight's Cross in that it could be upgraded, >but I'm not certain of that.
several notables have received the honor in different classes (Adm. Yamamoto, Adm. Kondo) but it's unclear whether the upgrade to 1st Class was because of extra-conspicuous bravery and leadership or because they already had one and that was the only place to go with a second award. Records are understandably thin on the ground given that a) some 600k of these were given out in WW2 (in all 7 classes, many posthumously), b) the award was abolished by the Supreme Commander of the Allied Powers of Occupied Japan in 1947, and c) the official records were destroyed in the fire bombing of Tokyo. So it looks like the answer is "sort of" :)
-Z who is still bored and snowed in
--- Remember kids: guns make you stupid, duct tape makes you smart.