Nikkeijin Visa

Hi. I'm a half-Japanese half-Filipina, with my father being the japanese. I've been to Japan for the first time two weeks ago and my desire to live and work there was lit furiously. :) So I thought of applying for Nikkeijin visa but I'm completely confused. I'm currently in Singapore, working. I'm thinking of asking help from the Japan Embassy here but if there's anyone who can help me and suggest a few things to ease the process and expense, I'm grateful to receive. Thank you. :)

"I'm a half-Japanese half-Filipina, with my father being the Japanese."
you have to prove it by official documents.

Hi Ken. I read that Koseki is needed. Do I need to personally request it? What I only have is my birth certificate with my father's name and stamp, which I'm not sure if valid or not as evidence.

you need to confirm that you are registered in your father's koseki.
if your birth certificate is written in Japanese and it was issued from city office in Japan, you have your koseki.
if so, you are a Japanese, you don't need to have a visa.

but, even if you are in that case, when you are more than 22 years old, you need to choose one nationality.

"Nikkeijin visa" I believe is for people who have some Japanese ancestry but whose parents are not Japanese citizens. In your case, since you have a Japanese parent, it is possible that you are a Japanese citizen, but even if you are not, you would need a "Child of Japanese National" visa.

Firstly you need to find out whether you are a Japanese citizen. Were your parents married at the time of your birth? Were you born in Japan? If not, was your birth reported to the Japanese authorities?

I'm not a japanese citizen 'coz I was born and raised in the Philippines. My mother and father are not married and I don't think my birth is reported in Japanese gov't. I'm 28y/o now. If Nikkeijin is not the visa that I'm eligible to apply, then what type of visa?

"Child of Japanese" visa, is not the same with Nikkeijin? I think my biggest problem will be the koseki tohon. In my birth certificate, there was my father's name and stamp with his address but when I tried searching the address in google maps, it's not showing. I don't even know if he's in Japan.

Here is the information about "Nikkeijin visa" provided by the Japanese embassy in the Philippines: https://www.ph.emb-japan.go.jp/files/000232593.pdf

They do lump together the two cases (children of Japanese nationals and those who have no Japanese parent) together for visa purposes, but for immigration purposes they are different. Look for yourself whether you can provide all the documents listed.

The Japanese embassy in Singapore does not issue this type of visa. If you want to apply for a visa in Singapore, you will first need to apply for a Certificate of Eligibility at the immigration bureau in Japan, under "Spouse or Child of Japanese National" status.

http://www.immi-moj.go.jp/english/tetuduki/kanri/shyorui/01.html

https://www.sg.emb-japan.go.jp/files/000365222.pdf

You have to prove your birth and father from the city ward then it's easy have some steps ahead to get it

it seems you don't have enough official information which proves you are a Japanese or a child of a Japanese. I think you need to consult (or hire) a lawyer.