I believe the tone is somewhat dramatic based on the dialogue such as "shot his hand out in front of him", it makes the story seem a lot more interesting than what it really is; a normal encounter.
Tone is the attitude an author takes toward his or her subject, characters, and readers. It is achieved through word choice (diction), sentence construction and word order (syntax), and by what the viewpoint character or the narrator focuses on.
I would say the general tone of this text is light and matter-of-factly. The speaker seems to be merely listing facts related to Joshua and Dong Soo's friendship, but she does not try to instigate feelings or emotional responses in her readers. We know the friends like each other, respect each other, and we know one of them is sociable while the other keeps to himself. Still, none of this is told in a way that would make readers like or dislike the characters. Frankly speaking, there isn't much depth to the story, no conflict other than Joshua's desire to learn about his friend's culture.