Nami Shiratori, with her pure and innocent charm, deeply cherished her days spent with her stepbrother. However, when they were forced to part ways and she began living alone, her feelings for him grew stronger each day, unable to forget the memories they shared. During this time, a certain teacher offered Nami special private lessons. Though she briefly found happiness by dating someone else, her emotions for her stepbrother remained overwhelming, intensifying her desire to reconnect with him. Then one day, her stepbrother suddenly showed up at her door, setting all her suppressed feelings into motion.