"Borderline experience" in its literal meaning is, what describes this anime best. The degeneracy is portrayed in such an exaggerated way that it feels like watching a parody of the whole “Ecchi” genre itself. Compared to other shows, where the ecchi aspect is often just an excuse for fanservice and more of a flair to the main premise, this one goes all the way in, until it hits the border of what can still be considered as ecchi.
It's like someone in the meeting room asked the question: “How can we make our male characters so degenerated, that it exceeds the usual cringe scale and reaches a point where it actually starts to get funny?” And boy, did they answer that question!

Another fatal flaw of not only genre representatives is, that they replace the “red-string” analogy regarding the story with more of a “puzzle” approach. They don’t think about an original storyline but rather grab a random piece out of the puzzle box that contains scenarios from other shows that worked before (If I see one more festival/firework episode, I might throw up). But not in this one. They somehow manage to not only answer the upper question, but also combine that with a unique, logical and coherent story. The final episode was more entertaining than all festivals and fireworks I saw so far combined.

I admit, I might interpret to much into this, and you clearly have to endure the first “shock” that this anime has to offer to get used to the humor, but if your able to look beyond the superficial degeneracy, you might experience a level of entertainment at least I didn’t expect from the cover and the given genres.

Hachimitsu Academy, one of the strictest girls' academies in Tokyo, has decided to admit boys into their system. Kiyoshi Fujino is one of these new boys, but he discovers to his shock that he and his four friends—Takehito "Gakuto" Morokuzu, Shingo Wakamoto, Jouji "Joe" Nezu, and Reiji "Andre" Andou—are the only male students among 1,000 girls. The draconian laws that are still in place make the school even worse, which punishes even the most minor infractions with a stay in the school's prison. The five boys all commit to voyeurism in the school's bathing area with the lecherous philosophy of "all for one, one for all". Their capture and "arrest" by the Underground Student Council causes the five boys to receive an ultimatum: either stay a month in the school's Prison Block or be expelled. The boys are incarcerated in the Prison Block together and Kiyoshi is overwhelmed by the discovery that all the other boys are masochists that revel in the punishments handed to them by their attractive but vicious supervisors.