Nana is a Mother 3 character, and a villager of Tazmily Village.
In Chapter 1, when playing as Flint, she will simply say, "I'm Nana. I like the ocean."
In Chapter 2, when playing as Duster, she can be found outside at nighttime when everyone else is indoors. When spoken to, she will mention Tanetane Island, and she muses why she knows the real truth about it while supposedly no one else does. Later, she can be found in Tazmily square, noting that none of the family members in the village really look alike, serving as a foreshadow to Leder's story in Chapter 8.
In Chapter 4, when Lucas approaches her, she warns him that he shouldn't talk to her, saying that everyone hates her due to her tendency to ramble. After that, the player is given the choice to talk to her, or rather, listen to her. If you say yes, you will go through the pain of listening to all of her rambling, causing Lucas and Boney to feel dizzy. The game humorously tells you that you should've turned back when you had the chance. If Nana is spoken to afterwards, she will tell Lucas that she thinks she could start to like him. The bulletin board by the Cross Road Station contains a message from Nana, which reads, "I have sand in my shoes, and I don't know what to do. Somebody do something!"
In Chapter 7, Nana will say that she's figured out her bad habit, and says, "I'll put it in one sentence. I never shut up." Later, when almost all of Tazmily's residents have moved to New Pork City, Nana is one of the very few remaining in the village, explaining that she's stuck in Tazmily because no one invited her to go with them, and she wonders when everyone suddenly got together to discuss leaving for the big city.
In Chapter 8, Nana is located outside the Empire Porky Building, and she says how she's waiting for the elevators to get fixed so she can use the upstairs bathroom.