Unexpected Apology

"Nii-san." 

She was shocked to see Takashi in her living room. Emilia sent her a message saying that his uncle was waiting for her at home. She replied to her that she really doesn't have an uncle, except those family friends in Cebu that she simply called uncle but not exactly their blood relatives. And they won't visit her in Berlin. 

In some parts of Asia, you called a man around their forties to fifties an uncle, even if they were strangers as a way of respect. However, when Emilia sent a message saying her uncle was waiting at home, it never occurred to her that it would be Takashi waiting for her. 

She blinked her eyes and closed her mouth that was dropped open when she saw him sitting casually in the living room. If he introduced himself as his uncle, does it mean that he already knew the secret of her birth? Does her mother tell him when she visited his family in Tokyo?