Shun's younger brother Fuyuki and his girlfriend Mamiya-san kissed.  When Shun finds out, he asks his friends what he should do as Fuyuki's older brother.
Fuyuki ignores his brother and goes on a date with Mamiya.  The gang decides to follow the couple on their date and end up at a karaoke box.
I don't think Fuyuki will 
learn his lesson that easily.
No creo que Fuyuki aprenda su lección tan fácilmente.
No creo que Fuyuki aprenda la lección tan fácilmente.
Não acho que o Fuyuki vai
 aprender a lição tão fácil.