[A non-human protagonist + the Fourth Calamity + farming management + behind-the-scenes plot + group portraits + search-and-fight] Le Ang, caught in a summoning ritual by a descendant of a noble, travels back in time as a gray rat hiding in the basement of a noble mansion, unexpectedly gaining the ability to summon players from Blue Star. Upon seeing the virtual reality game's realism, the Blue Star players, whose consciousnesses were summoned, become obsessed with their respective in-game characters—rats. As the game planner and the NPC boss to the rat players, Le Ang, while expanding his power through the supplies brought back by the players, learns extraordinary knowledge of this world from the descendants of the nobles... Gradually, Le Ang discovers that he has mastered alchemy. He transforms the frail rat players into his own creations. Flying squirrels with bat wings, muscular giant mutated rats...