The home-cleaning automaton Caret surprises Ikeda one day by arriving uninvited on his doorstep, announcing he is a lucky recipient of the "Life Improvement Project" by her inventor. Despite being charmed by her looks, Ikeda soon realizes that Caret is utterly useless at fulfilling her duty as a domestic assistant, leaving him with an unorthodox living arrangement with a less-than-capable robot and a sexually deviant roommate.