"Why do we have to focus on an unhappy future? I want to focus on the fun talk we were just having."
Because it pays to look at problems in a realistic manner and not bury your head in the ground, because otherwise they will come back to haunt you.
Seriously, I don't get this series and its moral lessons. Nagi behaved in a far more mature and sensible manner here than Erika or Sachi did 😕
Also, I'm with jaydoodle here, Nagi deserves a break. What has he ever done in the first place?