Route 1: Punishment ending
Route 2: Forgiveness ending
Route 3: Rescue ending
Route 4: True ending(Vanilla Ntr-Free)
Route 2&3 are just alternate endings to Route 1, playing out the same beside the ending.
To make things short, the MC is the true hero of the world. However, due to a cosmic screw-up, the fake hero was summoned from another world. This screw-up caused the hero powers meant for the MC to go into the fake hero instead. Not aware of this cosmic screw-up, the natives thought the fake hero was the true hero. Also unknown to the natives, the fake hero had reicieved an additional power, the power to brainwash women into his slaves.
Having recieved a "weak" power instead, the MC became the Hero party's porter/supporter.
The fake hero takes full advantage of his mind control power, secretly using it to turn countless women into his sex slaves. This unfortunately ends up including the other heroes, the MC's childhood friends. Not only did the fake hero's power brainwash the CHFs, it drastically altered their personalities, making them cold, hostile, & abusive to the mc.
The main heroine of the story is the literal goddess of this world, Yuno. She knew that if the MC didnt regain his position as the true hero, the world was doomed, as the fake hero would never be able to defeat the demon lord. However, despite being a goddess, there were restriction on her position that prevented her from taking direct action with her godly powers. So she reincarnated herself as a human named Yuno with most of her powers and memories sealed. She got herself taken into the Hero’s party as a slave. From there, she traveled with the MC, secretly transferring the hero's power from the fake hero into the MC.
She also kept the MC from falling into despair after having his fiance and CHFs ntr'd from him by the fake hero.
However, in Routes 1&2, Yuno is fatally injured during a battle with the demons, and the fake hero and the MC'S CHFs refused to help her, leading to her death. Her death, and the hero party's cold dismissal of it, nearly breaks the MC. Having turned back into her goddess form, yuno contacts the mc via a dream and reveals he is the true hero. She convinces him to keep fighting, as the hero power transfer was still ongoing despite her "death".
Driven by Yuno's words, MC stayed with the hero's party until the final battle with the demon lord. By that point the power transfer was complete, with the MC becoming the true hero and the fake became little different than a normal human. While the MC fought the demon armies, the fake was in depair, desperately trying to activate the hero's sword. Eventually the loss of the hero powers cripples the fake hero, causing his arms to disintegrate, and he is mentally and physically crippled, crying and defecating uncontrollably. His crippling also releases his victims and the MC's CHFs from his control. The MC goes on to defeat the demon lord by himself.