Yukimura and the others will be giving presentations at the summer study sessions. There's less than a month left until the training camp, but Kosuke still hasn't picked a research theme. Professor Ikeda suggests research into "an algorithm that could instantly find the True End in any dating game." On the other hand, Yukimura and Himuro are focused on the hormone which is released when a person is touched by someone they love - oxytocin. By investigating the amount present in a person's saliva, they think they might be able to determine if the person loves the one who touched them, and they decide to immediately put it to the test with some close contact...
We should have collected saliva back then.
.كان يجدر بنا جمع البيانات في ذلك الوقت
Wir hätten damals gleich noch
Speichelproben nehmen sollen.
Debimos reunir saliva esa vez.
Tendríamos que haber reunido
saliva aquella vez.
On aurait dû collecter notre salive
l’autre fois.
Avremmo dovuto raccogliere la saliva quella volta.
Devíamos ter coletado saliva
naquele momento.
Нужно было в прошлый раз 
взять слюну на анализ.