Yuuki Yuuna wa Yuusha de Aru

After defeating the Demon King, the heroes are on their way back home when they hear that a low-ranking succubus is causing trouble in a village, so they decide to defeat her with their childhood friend Celia, a holy mage.

My first summer vacation after enrolling at Shinpoku Academy— Mom became pregnant with my best friend's child.
“Ahh... oh, yes, Nagi-kun! Harder, faster! Pound the entrance to my baby-filled womb with your cock!”
Right before my eyes, my mother—Nishino Riho—is being held by my best friend, Terashima Nagi. My gentle, beloved mother is moaning, leaking a lewd, feminine voice unimaginable from her usual self, enjoying sex with my best friend Nagi's young penis.
Why? How did this happen? When did Mom and Nagi become intimate enough to have sex? Why is Mom pregnant with Nagi's baby instead of Dad's? I don't understand any of this.
No, I don't want to understand. As if to flaunt it to me, helpless and consumed by despair, Nagi thrusts his hips vigorously, taking my mother. My beloved mother, the most important person to me, has been taken by Nagi.
My gentle mother's eyes no longer look at me. They only look at Nagi. I can't forgive Nagi for having sex with Mom countless times behind my back and getting her pregnant! But Mom doesn't seem to mind in front of me.
Worse, she's accepting Nagi's penis with an expression of pleasure I've never seen before. Anger, hatred, despair... Amidst this jumble of emotions, I found myself intensely aroused by the sight of my mother, pleasured by my best friend, my own penis swelling with rage.
Nishino Riho is young, beautiful, and gentle. She possesses a voluptuous figure men adore—103cm I-cup breasts and a 99cm ample rear.
This mother cuckold story depicts how she betrayed her husband and their cherished only son, the protagonist “Nishino Ryota,” to drown in sex with Nagi, ultimately conceiving Nagi's child within her womb as a woman.
Driven by her lust, Riho surrenders to Nagi, a young, virile male brimming with sexual desire. Today, too, she steals glances from her beloved husband and son, drowning in carnal passion as she ripens.

The protagonist dies in a car accident and reincarnates as a god in a world entirely devoid of women, inhabited only by crossdressing boys (otokonoko). Furthermore, in this world, he is the only being who possesses the divine power to get them pregnant!
After successfully impregnating the three shrine maidens serving him—Hahamu, Mamamu, and Kokomu—the protagonist eagerly awaits the arrival of his children. One day, however, he discovers a mysterious crystal ball hidden deep within the temple.
As he wonders what it could be, the crystal ball suddenly emits a dazzling light. When the light finally subsides, everything appears completely unchanged at first glance.
However, as he questions what just happened, he notices that the temple has somehow become aged, weathered, and covered in filth. In a panic, he calls out to Hahamu and the others.
But instead of his familiars, three completely unknown crossdressing boys appear before him, claiming to be shrine maidens. They deliver a shocking revelation: this world is now on the brink of ruin.
What exactly happened to the protagonist’s reality? And will he be able to fulfill his duty as a god to save this dying world?