Anniversary: Memories of Summer Vacation tells the story of a young girl named Ringo. One night, Ringo witnesses an impish girl named Cherry seducing another girl. At first she feels repulsed, but after a while finds out that she is excited... soon she and Cherry become lovers and soulmates, unaware of the fact that Cherry is being hunted by the authorities...
The game is a traditional Japanese-style adventure (without puzzles). Interaction with the game world is performed by selected verb commands (Look, Talk, Think, Move, etc.), from a menu. Selecting a command leads to context-related sub-menus.
Sex scenes are handled somewhat differently; also with verb commands, but rather concrete ones (Touch, Lick, etc.), and point-and-click interaction instead of sub-menus.