A nearly-30-year-old office worker suddenly remembers that he was a powerful mage in a past life! Now, he switches back and forth between the two worlds, living a laid-back, slow-life existence. But one day, out of the blue, he's approached by a fierce female adventurer—from the legendary all-women Valkyrie party, rumored to hate men! Just what will happen to this near-30s mage's peaceful, dual-world life now!?