Japanese nationality

Hi, im planning to visit japan this coming november and to visit my long lost dad and get my new koseki tohon to get my japanese passport. I do have my dads koseki tohon but the embassy here in ph wont take it because it needs to be updated. And I dont have anyway of contacting my dad since he wont answer any international calls. I do have his passport copy, photos, and old documents. My questions are

1. Can I get my japanese passport in japan?
2. Are there any requirements for getting japanese passport?
3. How long will it take for me to get approve?
4. What type of visa should I get ?

If you are eligible for a Japanese passport as a citizen by birth, why not get it in the Philippines? You would have to provide all the normal documentation for it (identity documents). On a Japanese passport you will not need a visa to enter Japan.
Are you also going to drop your second nationality? Japan law does not allow dual citizenship.

I need to get a new koseki tohon and I don’t have any known family members besides my dad and my cousin. I asked my cousin before and she said she can’t do it since she lives in gunma. And I read that the only person can get koseki tohon are the names written on it.

"I need to get a new koseki tohon"
who's koseki tohon are you saying ? yours or your father's ?

"And I read that the only person can get koseki tohon are the names written on it. "
so, is there your name on the old koseki tohon you have ?

Sorry, my fathers koseki
And yes my name is written on it.

Apply by mail - that is allowed.

Law on Family Registry, Article 10, 戸籍法第10条