Which girl should I choose?

Which girl should I choose? is a Japanese adult romance visual novel which tells the story of Natsuki Hayami, a college student who lives alone with his little sister Koharu. When they are forced to move out of their home due to renovations, Natsuki and Koharu accept an offer from Natsuki's former teacher, Hinata Hiiragi, whom Natsuki once had a crush on, to live and work at the Hiiragi family's café. There, Natsuki meets Hinata's twin sister, who is also named Natsuki, a flirty novelist who likes to tease Natsuki by pretending to be her sister. As Natsuki Hayami grows accustomed to his new environment, he must decide whether he has romantic feelings for one of the Hiiragis, or whether he wants to be with one of the other people in his life, such as his beloved Koharu, his tomboy friend Koori Kujou, his aikido partner Suzuno Kisaragi, or his best friend Shizuma Kisaragi.

Like most visual novels, the gameplay revolves around navigating through the story by reading text and periodically making a decision that may influence the outcome of the plot, leading to multiple branching storylines and endings. Through the player's choices, various romantic storylines develop, leading to deepening relationships with the female characters. Some of these storylines include scenes with explicit sexual content. The game features voice acting for all significant characters except the protagonist.