Nidome no Natsu, Nidoto Aenai Kimi

He was just an ordinary high school boy, living through the mundane rhythm of classes and club activities, until she walked into his life. Moriyama Rin was a quiet enigma, a girl who carried the weight of an incurable disease behind a carefully maintained mask of normalcy. Drawn to her resilience and the fleeting beauty of her smile, he fell in love with her, knowing that their time together was measured not in years, but in precious, dwindling moments. Rin fought to keep her condition a secret, insisting on experiencing her youth without pity, and he honored that wish even as his heart ached with the foreknowledge of the inevitable. Their last cultural festival became the bittersweet culmination of their fragile happiness. On that stage, amid the noise and lights of their live concert, they shared a performance that felt like a final confession—a perfect, ephemeral memory sealed with a kiss as the festival drew to a close. But the joy of that night could not halt the progression of her illness. Soon after, Rin’s life ended, leaving him adrift in a void of regret and unanswered longing. Just as he was drowning in the grief of her absence, the world twisted. He was hurled backward through time, waking on the first day of that same high school year with the ghost of her death still fresh in his mind. Now burdened with the knowledge of her fate, he faces an agonizing dilemma: Can he rewrite their story and save her from the tragedy he knows is coming, or will the immutable laws of time force him to watch the girl he loves vanish once more, reliving every beautiful, heartbreaking moment exactly as it was?