Yeah, I'm not happy... The real world has crashed in, and all the sugary romance has evaporated. Why does Japan always have to do this? Why do they feel the need to torture themselves? They are really big on NTR and BSS (but I loved you first). They struggle to date, they never get married, they don't have kids, and their birth rate is well below the extinction threshold.
To be honest, this is doomed to failure. No matter what, they are going to be apart for a year, so what is the point? Why confess now, when the logistics are going to be impossible moving forward? I see it many times in novels/manga, people being determined to confess before they leave high school, as if they intend to lock themselves into a long-distance relationship, which will have a 95% failure rate. You go to college/university, and you will make new friendships and probably romantic relationships as you socialise. It all seems like madness to try to form a relationship at the point that most existing ones are entering their death throes.