What rank do I need for Drain quest?

[Tobold]

I know that a citizen of San d'Oria can enter the castle where you get the quest for the drain spell as soon as he reaches rank 2. But what if I am a citizen of another city? Is rank 2 still enough to enter the city? I don't want to travel all that way and then find myself barred at the door. Or can only San d'Orians do this quest?

I know I will also need some San d'Oria fame, but that I wanted to get anyway, for the gobbie bag in Jeuno.

[sabrina]

After accepting the offer of mission2-3, "Emissary" or "The Three Kingdoms", you will be able to enter the castle.

[jaby]

I heard you needed 15 Sans quests to enter the castle.
Might as well increase that rank with some crystal donations while you're at it.

Edit: rank != fame