There are 1,000 Korea-Japan international marriages per year, but 0 marriage-based naturalizations?

Excluding the pandemic seasons, more than 1,000 people have married every year for the past 20 years.

I went directly to the Statistics Korea website and checked the 2024 data for marriage-based naturalization.
The top 8 nationalities are listed, but there isn't a single case of a Japanese national naturalizing in Korea through marriage. Why???
Over 1,000 Korea-Japan couples marry, yet there are 0 marriage-based naturalizations?
For reference, looking at last year's nationality data for long-term resident foreign registrants...
Hmm, what is this...
After looking into it:
Naturalization: This is the procedure for pure foreigners with no blood or historical ties to Korea to obtain Korean nationality.
Japanese nationals of Zainichi Korean descent were originally Korean, so they are recorded under "Nationality Restoration" statistics rather than "Naturalization" statistics.
Nationality Restoration: This applies to Zainichi Koreans who previously held Korean nationality themselves or whose parents/grandparents held it.
Since Zainichi Koreans can prove their Korean lineage through their parents' Korean (Joseon) nationality at birth or via old family registers, they fall under "Nationality Restoration" rather than the naturalization process.
It turns out that in Korean statistics, "naturalization" only applies to pure Japanese nationals.
If a person of Korean descent naturalized as a Japanese citizen and then re-acquired Korean nationality by marrying a Korean, they are recorded as a "Nationality Restorer" rather than a "Naturalizer" in the statistics.
Is it something like this???


Entertainer Jung Joon-ha married a Japanese woman of Zainichi Korean descent and has a son.
Singer Kangnam, who is of Zainichi Korean descent, married national speed skater Lee Sang-hwa.
It seems like these cases are all being recorded as "Japanese."
Aside from a few "pure" Japanese nationals who become famous on YouTube, it seems most of the underlying statistics consist of Japanese nationals of Zainichi Korean descent.
Also, seeing that the volume of Korea-Japan international marriages has remained consistently around 1,000 per year for the past 20 years,
it seems like a system of fixed brokers has been established within international marriage agencies to connect Zainichi Koreans with Koreans.
There also seems to be a volume of mass marriages among Zainichi Koreans in the Unification Church.
Just like the brokers who facilitate international marriages with Chinese nationals, where the majority of those marriages are actually with ethnic Koreans (Joseonjok) recorded as Chinese.
Conclusion: Most Japanese women marrying Koreans are Japanese women of Zainichi Korean descent.