Model student Nanase Jin—well-behaved, excellent grades, and highly regarded by those around him—harbors dreams for his future. However, he suddenly receives a terminal diagnosis of one year to live from a doctor. While dejectedly walking home, Jin is suddenly pulled into another world! In that world, monsters bearing playing card marks appear, and after somehow managing to defeat a monster, Jin hears system-like announcements and gains the power and lifespan of that playing card. Jin resolves to use the card’s power to obtain as many cards as possible and extend his lifespan. Having found hope to live amidst the despair of his terminal diagnosis, will Jin be able to overcome the crises and survive?