What was North Korea like before Kim Jong Sung took power?

I’m not sure which one you mean. The three names are
• Kim Il-sung (installed in 1948)
• Kim Jong-il (succeeded in 1994)
• Kim Jong-un (succeeded in 2012)
There are variants on the spelling because Korean is not written in our (Roman) alphabet, but the name you gave is sort of a blend.

Even though it can be hard to get a clear picture because North Korea has its own version of history, there are books and other sources on the subject.

There’s a lot of information in the book called Nothing to Envy: Ordinary Lives in North Korea, by Barbara Demick. It’s mostly about people struggling to survive under the current regime, which began with Kim Il-sung, continued with his son Kim Jong-il, and is now led by his grandson Kim Jong-un. But there is a chapter that covers the history of how Kim Il-sung came to power when Korea was divided into North and South in 1948 and he became the leader of North Korea.

It was not very developed at all, and, along with South Korea, had been subjugated under the Japanese thumb for many years. There was a period about the turn of the last century where Korea was freed from Chinese and Russian rule, and began some initial modernization. But in 1910, it became a colony of Japan, and its development was only in tribute to Japan.

The Kim family has run N Korea since Korea was divided after WWII.

I think you should clarify that you are asking about what life was like in the Empire of Japan on the spot of land which is now North Korea? Or are you asking about something else?

Sorry for mixing up the names, I was really tired and kept messing up names lol. It’s confusing. I was asking about specifically the spot that is North Korea I guess. Just how Korea was before it was split.