The sons can't help but be obsessed with their stepmother Kana, who always goes braless at home. After their father's remarriage, the brothers had secretly wanted to grow closer to the beautiful and kind Kana, but their relationship remained awkward and strained. That tense dynamic finally shattered when Kana noticed the unnervingly intense gaze of her stepsons fixated on her breasts. "…Are you interested?" Unwilling to provoke conflict, Kana, despite her hesitation, decides to expose her breasts to her stepsons—even if just a little—and invites them to touch freely, under the condition it remains limited. "Really? Are you sure?" the sons ask, swallowing hard. At this moment, Kana still has no idea what's about to unfold.