It is to protect the prosperity of military commanders and soldiers. The lingua franca is "national prosperity"
This word is divided into two parts, but generally speaking, it was copied from China by the Japanese, so I will say them one by one.
At first, in the Southern and Northern Dynasties, there appeared some vocabulary terms about Wu Yun, such as "Wu Yun was long, Wu Yun ended". Obviously, this kind of writing appeared in the era when the soldiers fought and went through years of chaos. For example, in Wen Hui, Prince of the Southern Qi Dynasty, it is said here: "The king of the guard knows that although the writing is beautiful, the martial arts will eventually die, and the young will spread quickly."
The Japanese say "Wu Yun", not "Wu Yun Chang Long", and the corresponding Chinese translation is "Wu Yun Chang Long". Please understand the following differences carefully. The Japanese speak Japanese, not Chinese. I find many people very confusing. If the Japanese army said something in World War II, the Chinese translator can't say anything. This logic will be strange. This is one of them.
Five clouds are a greeting, similar to getting a great start, lasting success and so on. And there are no restrictions on the use of scenarios. For example, before the exam, the teacher will say to the students, I wish you a good start, and before the competition, the Japanese coach will also say "five clouds grow long" to the athletes, and it will often appear in various scenes of animation, because it is just an ordinary and ordinary greeting. This is the second one.