Though Yukimura and Himuro went as far as to kiss for the experiment, they were soundly beaten by Chris and Suiu's oxytocin levels in their saliva. Panicked, Yukimura suggests that they conduct control experiments. However, in the midst of the Yukimura/Suiu pairing, Suiu's seductive manner ends up causing Yukimura to ogle her charms. Seeing that, Himuro runs another experiment with Yukimura, but ends up sulking. The two end up having a lover's quarrel. Yukimura's behavior causes Chris to look down at him coldly and say, "As a man, you are a failure."
It's impossible not to be happy! 
Totally impossible!
!من المستحيل ألا أشعر بالسعادة! هذا غير ممكن
Wie soll man sich da nicht freuen?
Geht doch gar nicht!
¡Sería imposible que no me alegrara!
¡Imposible!
¡Sería imposible que no me alegrara!
¡Imposible!
N’essaie pas de m’en empêcher,
c’est impossible !
È impossibile non essere felici!
Completamente impossibile!
Não tem como não
ficar feliz! É impossível!
Невозможно не испытывать
чувство счастья! Невозможно!