A couple in swimsuits relaxing at a beach in Shonan decide to take on a swapping game! This intense and heated game has a simple rule: the goal is to make the other person's partner climax more times than your own partner to win. ———— The pair of Konatsu (22) and Akihito (35). Konatsu is a cute-faced, big-titted F-cup girl, while Akihito is a tall, handsome-voiced man. On the other side are Nana (21) and Chiaki (23), a stunning, extra-large G-cup beauty paired with a classic good-looking guy. ———— The game's objective? To bring the opponent to ejaculation or orgasm more times than your own partner, right in front of your lover. Despite the simple rules, the erotic dialogue intensifies quickly. Lines like "Should I move my hips more?" and "I'm about to come, please stop…" perfectly capture the escalating arousal between them. With prize money on the line, the NTR-style, zero-distance action sends both couples into uncontrollable excitement. The laid-back beach atmosphere vanishes completely, spiraling into a situation no one can stop. This scene marks the beginning of an erotic story where love and desire collide.