Amanomiya Koyoi is one of the heroines featured in Monster Girl Encyclopedia World Guide I: Fallen Maidens, and the parallel tales of Monster Girl Encyclopedia Stories: Fallen Brides.

Fallen Maidens biography (pre-transformation)

A monster slayer from an eastern island country, Zipangu. She’s quiet and has difficulty expressing her feelings, but she’s really a gentle woman with a devoted personality who serves the people.

The Amanomiya family resides in a region that is hostile toward monsters and they have served as monster slayers for generations. She’s the second daughter out of 3 sisters in the family and all three of them were ordained to become monster slayers from the time they were born. In order to raise excellent monster slayers, the Amanomiya family is bound by many traditions, all pleasure is forbidden and only those chosen by their parents are allowed to be their friends. Of course, romantic affairs with the opposite sex are totally out of the question. In order to strengthen the blood of the monster slayers, their marriage partners are predetermined. There is no room whatsoever for an individual’s free will.

The Amanomiya family has only one official successor and the rest become branch families. Those of the branch families don’t shoulder such a heavy burden. For that reason, in order to free her beloved elder and younger sisters, she sacrificed everything and trained hard as a monster slayer. However, her younger sister wasn’t able to bear life in the Amanomiya family. At the time when her younger sister disappeared, the light of emotion completely disappeared from her eyes. She became unable to consider anything, unable to feel anything and continued her training.

In this way, she acquired unique talent as a monster slayer and became someone of great importance to the Amanomiya family. However, she wasn’t the only one with this goal. Her elder sister had also grown into a first-rate monster slayer for the sake of freeing her younger sisters. Because of a dispute in determining the successor, the people related to the Amanomiya family ended up splitting into two factions and fighting. In the midst of this conflict, her elder sister was marked for death and although she managed to evade death, she ended up getting seriously wounded. Unable to bear the fact that her presence in the Amanomiya family was what led to her beloved sister getting injured, she left home without telling anyone.

In this way, she ended up leaving Zipangu and visiting the continent. She earned a living daily using the powers of a monster slayer. The Order was recruiting in the place where she lived, an anti-monster territory and she was to join in an operation for the reclamation of Lescatie and exterminate the monsters infesting it. From the place that was formerly the holy religious kingdom of Lescatie, she could sense only an aura of foul wickedness. While sacrificing many comrades and evading monsters who attacked her throughout the city, she managed to somehow make it by herself to the place where the wicked aura was thickest, the royal castle which could be considered the heart of the kingdom. What she witnessed when she visited the throne room was the incredibly lewd spectacle of one man and many monsters having sex.

Don’t over do it, you two... I’ll do everything... I will...

–Amanomiya Koyoi , Fallen Maidens

Fallen Maidens biography (post-transformation)

Koyoi Inari1

Inari Koyoi

She was shocked as she watched what could only be called an obscene spectacle of utter debauchery unfold before her very eyes. One succubus straddled the man and worked her hips, while another monster frantically sucked the man’s lips and another monster took the man’s hand and placed it in her own genitalia… Also, while clinging to the man’s chest and feet, the monsters waiting to get in on the action went at it together, indulging in pleasure. The man’s body shuddered noticeably and when he blew his load, the monster who was straddling him switched places with a monster waiting on the side and they changed roles. The feast of pleasure continued, turn after turn after turn.

Although she managed to make it there, her body was already in the process of being corrupted by the thick demonic energy and her heart was as well, because instead of being disgusted by the spectacle she was fascinated by it. She couldn’t stop watching. In the place of the succubus with aqua colored hair, a young witch straddled the man and had him ejaculate inside her. In an instant the thick odor of semen tickling her nose. Although it was her first time smelling the odor instinctive knowledge was already beginning to take root, telling her that it was a man’s semen, the best treat.

When the witch raised her hips with a satisfied look on her face, a hard swelling that still hadn’t lost strength and was so enormous that it was puzzling how it could have fit inside the witch, caught her eyes. It was her first time seeing it, but instinct told her that it was a man’s penis, a thing for penetrating women and giving them pleasure. Her thoughts had been completely corrupted by demonic influence. Oh, how she wanted to join in on the action. If he could release that delicious smelling odor and make her womb throb intensely, then surely he would fuck her brains out. She wanted him to pierce her with that thing and destroy all the values she had held onto thus far in life.

She wanted him to pour plenty of that sweet, thick semen inside her and wash away her misspent life, staining it pure white. She wanted to have sex with that man too, she wanted to service that man too. She wanted to join with that man too. Then suddenly, a beautiful succubus with white wings appeared from behind and embraced her flushing female body. When the succubus took her hand, the witch withdrew and she was led before the available man…

In this way Amanomiya Koyoi cast aside her humanity, being reborn as an "inari". Inari are devoted, and unlike the "youko" that release their demonic energy indiscriminately, igniting the passions of humans and monsters, they are a race that controls their demonic energy, only pouring it into their beloved husbands.

She was deeply in love with "you"‎, her master that caused her to fall. She poured demonic energy into "you" endlessly, heightening your power as an incubus so that "you" can use her and enjoy yourself more. She also loved her friends that love “you” in the same way. In order to please you more together, she poured her demonic energy out endlessly, changing her friends into even lewder and more powerful monsters.

And she also loved this kingdom. It destroyed the prison inside of herself known as the “Amanomiya” that she had been trapped in. There was no order, no rules, and no harming loved ones. It was nice because there was only seeking the man she loves.

Please, master... leave everything to me, your loyal vixen... Pour more and more spirit energy into me... I’ll make this paradise for you more and more wonderful, master... more and more into a lewd kingdom of your liking...

–Amanomiya Koyoi , Fallen Maidens

Fallen Brides story

Case 7: Koyoi - Black Falls, Pink Dawns is provided free of charge. All credits for the materials within go to their respective authors. English translation provided by OtherSideofSky.

Translation progress:

First Draft - 17,190/17,190 (100%)

Original host

Pastebin (raw):
MD5: 949F4982F235AB8EE8052D75EC6CEDA1
Mobi: n/a