Kana Imouto focuses on storytelling, and falls into the subgenre of dating sims which are full of tragic events and meant to be emotionally moving for the player.
The story of Taka and his little sister Kana is told from Taka's perspective, starting when Kana is just about to start high school and then delving into the past to explore the relationship between the two siblings.
The game is a visual novel, displaying scenery and characters in the background while the characters' dialogue and Taka's narration are displayed as text. Music and sound effects are also used. The unhurried narration is intended to allow the player to identify with Taka (and Kana) as the story unfolds.
Over the course of the game, the player is presented with approximately 30 decision points which determine which path the storyline will follow and, ultimately, which ending the player will achieve.