20 year-old Leo Salazar felt like he was just going through the motions in life with nothing going for him. When a he was suddenly was summoned to another world he believed that this would be just the break he needed. However, reality was always crueler than fantasy. Once he arrived... The Hero Party that summoned him was already Dead!

What made matters worse was that he ends getting saddled with a request more daunting than saving the world; protecting a young seemingly emotionless girl. Armed with the powers of the fallen heroes can Leo handle this responsibility that was thrust upon him? Or will he fail to live up the expectations like he has done back in his world? After all, "How the hell do I take care of an Assassin!"