answer: Jack tells #Person1# he is staying here during the vacation to gain some working experience while #Person1# is leaving for home.
documents: #Person1#: Hi, Jack. Who are you writing to?
  #Person2#: I'm writing to my parents telling them I'll stay here this summer.
  #Person1#: You're not going home? I thought you were going on a trip to Japan with your family.
  #Person2#: Well, I intended to go with them, but I thought again and changed my mind.
  #Person1#: Tell me. I'm interested in knowing what keeps you from joining your beloved family and staying here. It certainly is not studying.
  #Person2#: No, certainly not. Michael arranged for me to work at his uncle's institution.
  #Person1#: How much will you be paid?
  #Person2#: Judy, I don't do it for money, but for experience. Besides, it's voluntary work.
  #Person1#: You work without payment? That's really something.
  #Person2#: When will you leave for home?
  #Person1#: Tomorrow. We'll fly to Hawaii two days after. I really have to pack now.
  #Person2#: Go then. Have a nice vacation!
  #Person1#: I'll send you postcards.