Multiple subdomains with separate menu’s and content

I am asked to develop a website for a school with 24 classes. The main website will contain general information and will be built up off informative pages and a blog for news. No problem so far.

But, there must be 24 subsites (1 per class) accessible through subdomains like class1.school.com, class2.school.com, etc. Each subsite must look the same (same template?), but must have its own content consisting of an own menu, informative pages and its own blog for news.

WP users should be appointed to one or more subsites, so the teacher from Class 1 can only modify the content on class1.school.com and the director can modify the content on all subsites.

I have made a lot of WP websites, but mostly pretty basic sites. Can anyone point me in the right direction for this project? Is there an “easy” yet stable solution possible? Should I look at the Multisite feature? Or can I use some kind of community / role plugin (perhaps Buddypress)? Or is this quite difficult and should I point them to a WP specialist who can make custom solutions/plugins?