Natsumi's self-invitation didn't affect the tour itself since it was just an additional headcount for the group. Besides, Natsumi stuck to Hajime like glue, which implied that she wouldn't be separating from the group anytime soon. This gesture made Megumi bite her fingernails, though, but she didn't show her slight annoyance outwardly, probably because she had a reputation to keep up— a pretense to show to the son of their business partner, Mizunari Keiichi.
Chapter 1/2 update today. Have a great day everyone!