He Said, "I Can't Love You" Because the Saint Was Coming, So I Became a Figurehead Queen... But the Saint Was Just Five, So I Went All-In on Parenting!!

King Yuri is bound by tradition to marry the Saint, so fiancée Edeline accepts life as a mere "figurehead queen." Until the Saint appears as a scared five-year-old named Ai. Adopting the child, Yuri and Edeline forge an unexpected family whose love may become the kingdom's greatest power.

(Source: MangaPlaza)