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." (thetvdb.com)