Yu, an office worker, was exhausted both physically and mentally after working late into the night every day at a black company. The moment he wished for healing, he was suddenly summoned to another world. He was summoned by a beautiful elf woman, Laranoa. According to her, the human race (elves) of this world faced a serious problem: a lack of reproductive instinct in men prevented them from having offspring. Yu was summoned as the savior of humanity. The women were overwhelmed with their bodies and maternal instincts, leading difficult days. Elves are long-lived and upon learning that Yu is only 22 years old, her maternal instincts instantly overflowed. "I'm your mother here" she said, embracing Yu and enveloped in her motherly warmth. A long-forgotten sense of security lulled him to sleep and he finally found a peaceful sleep for the first time in a long time in the other world. Even though he was treated like a baby, Yu was a grown man. The next morning, when Laranoa, naked, invited him to take a bath, the proof that he was the savior rose to prominence! Laranoa sees this and is overjoyed, believing Yuu to be her savior! And then, excited, Laranoa starts to produce breast milk...! Apparently, elves in this world produce breast milk when they're aroused. Soothed by Laranoa's love, Yuu enjoys a sweet and erotic life in another world! Can Yuu really save this world? Or will "Mama" monopolize him?