Japinoy with mother’s surname

My son is Japinoy, i conceived him in Japan and he was born in the Philippines. I used my surname as his surname, i asked help from an NGO before and i gave them my documents but unfortunately they moved to another place and i lost contact with them. my son is now 12 years old, and he wants to meet his father, but unfortunately we lost contact. i have his address and his home number was changed though i got another number i believe is their mobile number, about 2 weeks ago i tried to contact him and his mother answered, our conversation was cut short when my load run out. i tried contacting again but they wouldn't answer anymore. i just want some help, or if not i want me and my son to go in Japan and i want to find work to support him. I only want what's best for my son and I believe he deserves to meet his father and be there. Can somebody help me? What should i do? Thanks in advance.

If an unmarried Japanese father and non-Japanese mother have a child, the parents later marry, and the Japanese father acknowledges paternity, the child can acquire Japanese nationality, so long as the child has not reached the age of 20.
Since the Japanese nationality law effective from 1985 mention that if the parents are not married at the time of birth and the father has not acknowledged paternity while the child was still in the womb, the child will not acquire Japanese nationality.

If you want to apply for work or want to live in Japan you need to get in touch with the father and ask for support. If not you have to go to the same procedure as anyone else.

Thank you for your reply!
When i gave birth to my son his father still supports us, after about two years he suddenly stopped. Then after about two years he re-appeared and gave support. after one and a half year he suddenly stopped and haven't heard from him since then. I have documents he signed for my childs birth certificate but i had a hard time registering him before because the national statistic office requires me a lot of papers and said his father needs to come here, and they were asking me a large amount of money that's why i named my son's surname after me... Those papers his father signed and his fathers documents like kosekitohon etc. i submitted to Shin-Nikkeijin an NGO here in the Philippines, but i haven't heard from them, and they already moved to a different address. I don't know if i can still get them... and if they can still help me ..