The Overdemandingness Objection maintains that an ethical theory or principle that demands too much should be rejected, or at least moderated. Traditionally, overdemandingness is considered primarily a problem for consequentialist ethical theories. Recently, Kant and Kantian ethics have also become part of the debate. This development helps us better understand both overdemandingness and problems with Kant's ethics. In this, the first of a pair of papers, we introduce the distinction between perfect and imperfect duties as well as a framework for understanding the overdemandingness objection that allows us to discuss overdemandingness across different ethical theories. We then consider two ways that Kantians have sought to avoid the implication that imperfect duties may be overly demanding: (1) via the latitude of imperfect duties, and (2) by the suggestion that the wider system of duties is self-moderating. We conclude that it is unclear whether the two most prominent ways of addressing the overdemandingness objection work, challenging them on their own terms, and observing that they are inapplicable to potential demandingness concerns pertaining to perfect duties.