A man grieving for Nanako, a hostess he knew, says he wants to see her again, and suddenly a woman's voice answers him.
Culture note At Japanese hostess clubs, customers can pay extra to 'nominate' (shimei) a specific hostess to sit with them.
The words appear when the audience laughs.
えまさかナナコさん本当に会いに来てくれたんですか
Wait, no way... Nanako, you really came to see me?
Textbookえっ、まさか、ナナコさんが本当に会いに来てくださったのですか。Instead of a full sentence like 「信じられません」, the speaker blurts 「まさか」 ('no way') right before the question they can hardly believe.