Hajime entered a boarding school at the same time his father remarried, and is now on the verge of graduation after three years away. Over time, his initial feelings for his stepmother, Mihana, had faded, and he never expected to fall in love again. But on graduation day, seeing Mihana running toward him with a bright smile reignites the flame in his heart. Excited about their private celebration, Hajime tries to suppress his growing desire for the vulnerable Mihana as he escorts her to a hotel. Then Mihana says, "A gift for the now-adult Hajime-kun," and gently kisses him. Once again, he takes another step into adulthood—.