In 'Whose Hello?', players assume the role of a quirky anthropomorphized greeting card detective in a vibrant city where cards come to life. With an unexpected twist, the game begins at the annual 'Hello Festival,' where all the greeting cards gather to celebrate the art of salutation. This year, however, the festivities are interrupted when a beloved card, known for its iconic greeting, goes missing just before the crucial 'Most Creative Hello' contest. Players must navigate through various card-themed districts, interact with witty and eccentric card characters, gather clues, solve riddles, and uncover the mystery of who is behind the card-napping while also learning about the unique greetings that represent cultures around the world. Every choice impacts the narrative and leads to multiple endings, ensuring that no two playthroughs are the same.