Man'yoshu is the Japanese oldest tanka collection. It contains over 4 thousand old tanka created in the 7th century or the 8th. It is so far that we are hard to get who edited and compiled the collection. Some say Otomo-no Yakamochi did it, but nobody can attest now. Time flies, everything goes by. It is difficult to know what it was really.
How do you feel? It is easy to imagine some will say "I feel kind of jealousy, we don't know what it was at the time in our nation." American may think that they didn't have America herself in the 7th century. It is too far to know easily. And I suppose Japanese people are also hard to access though they have Man'yoshu.
Why? The tanka were all written in kanji (Chinese characters). Today Japanese people use hiragana, katakana, & kanji together for writing something in Japan.
In the 8th century, Japan didn't have their original characters. So they had to use the characters from China via Korea when they wrote something. We don't know accurately when hiragana and katakana first appeared in Japan. What is the first story all written in hiragana? It is the Tale of the Bamboo Cutter which came out after about 100 years of appearance of Man'yoshu. Then it is easy to suppose hiragana and katakana were not there yet when Man'yoshu compiled.
Reading original Man'yoshu is hard for most people. And there are some they translated Man'yoshu into modern Japanese language. So it is not so hard to access the old world today if you are familiar with modern Japanese language.