Rokuro Saito is an ordinary Japanese high school student. Summer vacation has arrived, and, as it often happens, he is out of money. Then he hears that Kawarazaki, a wealthy and powerful magnate, needs someone to take care of his mansion during his absence. When the boy arrives there, he is surprised to discover that the mansion is mostly populated by young attractive women - relatives, employees, maids, etc. Naturally, he is willing to concentrate on his job only inasmuch as it doesn't impede his advancements on the other "mission" - get friendly with every girl and... you know the drill. However, soon he begins to realize that something more sinister is going on in the mansion... Kawarazakike no Ichizoku is a visual novel. The entire gameplay consists of occasional selection of a response and/or action from a menu. The rest of the game is dedicated to text accompanied by still pictures. Depending on the player's choices, different cutscenes will be triggered, and the player will achieve different endings, including several "bad" ones.