I've spent my whole life walking on thin ice, faithfully keeping my vow of purity, never breaking it!" "…You ask what happened to them?" "Hey! As a holy knight, does that count as breaking a precept?" "Besides, monster girls aren't human!" Herbert was reborn. Good news: he's a holy knight. Bad news: having taken the *Pure Vow*, he must stay pure his entire life! Great, he starts off with a magical ring on his finger. This life finally has…! Not only that, he's assigned to a prison to reform the most ferocious, terrifying non‑human inmates. Crazy dragons, fallen angels, dark elves, sea monsters, demons, devils… He’s supposed to reform them? For real? The weak, helpless him is no match for these monster girls and can only huddle in a corner, knees to his chest, trembling. Just when Herbert thinks he'll spend his whole life suppressing desire and die a miserable death in that prison, some evil god forcibly blesses him, granting him a special charm that makes every monster girl swoon. After that… things start to go off the rails. When Herbert steps back into the prison, he sees that the monster girls who once eyed him with hostility now look at him differently— they’re all craving his body! It’s at that moment he suddenly realizes they might not be as scary as they appear. They’re actually worth reforming!

The book is also known as *Guide to Evaluating Exotic Girls*, *Raising Monster Girls in Prison* 【Light‑hearted】【No morals】【Easy‑going】. It’s a completed work of over five million words, never a eunuch, character integrity guaranteed!