Holy Slave Princess Chloe - Until "The Strongest" Sinks to Power

St. Lilium Academy.
Under the school motto of "Be noble as a lily," this prestigious academy values the independence and self-reliance of its students.
The academy has long produced many outstanding students in the fields of academics, sports, and the arts, but it has a hidden side that must never be revealed.
The Nanjo family.
An illegal continental organisation that engages in various evil deeds, including human trafficking, is said to be controlling the academy from behind the scenes.
The Nishiki family is in conflict with Nanjo.
To the Nishiki family, who have built up strong connections in the political and financial world through the sale of sex slaves, the Nanjo family, who also engages in human trafficking, is a troublesome competitor.
In order to weaken Nanjo's power, Nishiki sends a man as an assassin to St. Lilium Academy.

Charlotte, princess of the Central Kingdom, renowned as one of the world’s leading military powers.

St Mary's Church holds many big breasted sisters. Some of them crave for uncontrollable pleasures. And today wishes come true.

I'm getting slightly conflicting information about the plot of the VN Saint Dorei Gakuen. Some sources I've found seem to indicate that this is your classic corrupt school with a perverted teacher who kidnaps unwilling female students. If that is the case, hard pass on this title for me. Other sources seem to suggest that female students enrolled in this school knowingly and willingly, expecting to be trained into slaves, whether eagerly or reluctantly is another question. If this is the case, this title is just far enough from the norm that I might actually take a second look at it.
 
Does anybody know which is actually the truth of the matter?

A mysterious dungeon suddenly appears in the city, and many people begin to go missing near its perimeter.
To uncover the truth and rescue those who have disappeared, the city’s justice-protecting transforming heroine — Holy Illusion Masked Princess, Aurora Crystal — enters the dungeon together with her partner, Kuroe.
During their initial investigation, Crystal discovers a strange core machine. After destroying it, a hologram of a young girl appears.
The girl introduces herself as Mashi.She explains to Crystal how the dungeon came to exist and states that all core machines must be destroyed, and the core terminal at the deepest level must be eliminated, or the true mastermind cannot be defeated.
Mashi pleads for Crystal to stop Droug’s ambitions, and Crystal accepts without hesitation.
Guided by Mashi, Crystal destroys each scattered core machine one by one, gradually opening the path to the deepest part of the dungeon.
Along the way, conversations with Mashi reveal her past, and Crystal slowly uncovers the full story behind the incident.
Finally, understanding everything that has led to this crisis, Crystal prepares to confront the true mastermind lurking at the bottom of the dungeon…