Millionaire and CEO of Obsidian Games, Kuroo Tetsurou is not a family man. Never has been, never will be -- at least, that's what he thinks before a set of triplets is left at his doorstep in the middle of the night, the result of a drunken one-night-stand gone wrong. Unemployed and heartbroken kindergarten teacher, Kozume Kenma loves kids -- err, most of the time. It also makes him desperate for a job; when he finds a job advertisement for a well-paying job as a live-in nanny, he thinks it's the perfect opportunity to get himself back on his feet until he finds another job as a teacher. And both of them wildly underestimated the power of three babies, and each other's power to make their lives better.