2 Shot Diary is a collection of twelve short episodes of sexual nature, each told by a different young woman, presented as entries in their diaries. There is no connection between the stories. Each heroine has a different profession and social status (high school student, nurse, model, etc.), where each episode usually centers around a particular sexual theme (voyeurism, lesbian sex, rape, etc.). The game is almost entirely pornographic, with nearly each screen being a depiction of a sexual activity.
The game may be considered a visual novel, because no skill whatsoever is required to play the game and most of it is composed of text accompanied by pictures rather than interaction. Instead of making decisions, characteristically for most visual novels, the player chooses words from a menu to insert into the text. If the choice makes no sense, it simply disappears and the player chooses another one.