Both titles are centered on a school setting with an all girl's school. Which the level of suspense it different, GGL focusing more on 'battles' whereas Zanokokuna focuses on 'audience approval', the actions of an individual affect the group and the reality of the situation affects the real world.
A similar situation where a group of students is being manipulated by a larger power; 3-nen being manipulated by their teacher and Zankokuna by the unforgiving net and potential setbacks that come with failing. The group must make decisions that will ultimately punish an individual if the group fails, and vice versa.