Musashi lives with his older sisters Nanami and Misaki, who often use him to their advantage. Lately he’s been getting closer to his cousins Kazuha and Honoka who live next door. It’s like they’re part of his family, or are they like lovers? Either way, every day is full of happiness. One day, Honoka suddenly confesses to Musashi that she loved him ever since she was born, asking him to become her groom! Suddenly, the delicate balance has been broken and each girl aimed to claim him as their own.