>From what I know its said that koreans and japanese are related and how they came from korea.
Related:Yes
came from Korea
artially yes, but not for all.
It is true that many - not ignorable - number of Korean people came to Japan. But Island were not empty. There were native Japanese and Korean people were Japanized in Japan.
> japanese has the same vowel and phonetics of korean language
No Japanese and no Korean agree with it. Who told you that? Western scholar who speaks neither Japanese nor Korean? Can you find if the spoken word is Chinese/Korean/japanese ? Most of Chinese/Korean/Japanese will find the difference between them though they could not read the meanings of them.
>Japanese emperor Akihito admitted that he's of korean blood and his emperial royal family came from korea along with its culture.
As for the blood, it would be true. but as for the royal family and culture, it is doubtful. Can you provide the information source?