I have absolutely no idea why this manga has a relatively low score. The series is easily one of the best I've read throughout the last two years. In fact, I'd put it straight into my top 10.
Are you ready to face a rather harsh reality?
No?
Neither are the students entering a meeting with the 'Dream Crusher'—an incredibly unorthodox guidance counselor. His stern advice meets the rose-colored glasses of juvenile years. On a case-by-case basis, the manga follows what happens with the students' lives post-graduation.
Three words to describe 'Yumenashi-sensei': mature, realistic, and insightful. It peeks at adult life in contemporary Japan in a way not many series do. A pure work of seinen art, it spares no sordid details - but it also gives salvation to those whose hopes were scarred by everyday life.
It's not a 100% fitting comparison, but imagine if 'Great Teacher Onizuka' was set in a university, there were no comedy bits, and the life advice (and lessons) were on the bleaker side of things. That's what this manga is essentially, and it works superbly well.
If you want a well-structured, mature read - look no further. This one's a treat.