「あーちん…何周目？」「…え？」――人生４周目の麻美（安藤サクラ）は、宇野真里（水川あさみ）にやり直しの人生を見抜かれてびっくり！同じように人生をやり直し続けている真里は、ずっと前から麻美のやり直しに感づいて、何度も鎌をかけていたらしい。
言われてみれば、中学時代のラウンドワンや成人式で真里の会話は不自然だった…。
真里が人生を何度もやり直しているワケも、麻美と同じく来世も人間に生まれ変わりたいから。でもそれとは別に、もう１つ大事な目的があるようで……。
真里の口から語られる、麻美も知らない“もうひとつの人生”…！繰り返す麻美の人生で起きていた何気ない出来事たちの裏に隠されていた衝撃の事実！そしてついに麻美が目標達成！？物語は誰も予想しなかった展開へと突き進む！！
'Ah-Ching... how many laps?' ...What?" --Asami (Ando Sakura), who is in the fourth round of her life, is surprised when Uno Mari (Mizukawa Asami) sees that she is starting her life over! It seems that Mari, who has also been redoing her life, sensed Asami's redoing a long time ago and repeatedly scythed at her. If you ask me, Mari's conversations at Round One in junior high school and at the coming-of-age ceremony were unnatural... The reason why Mari is starting her life over again and again is because, like Asami, she wants to be reincarnated as a human being in her next life. But apart from that, she seems to have another important purpose. ...... Mari tells her of "another life" that even Asami doesn't know about..! The shocking fact that was hidden behind the casual events that were happening in Asami's life over and over again! And finally, Asami achieves her goal! The story takes a turn no one expected!
