One day, a baby was abandoned at the Demon King's castle, known as the Castle of Death. Facing the crying infant, the strongest Demon King, Lucifer, said—— "I'll make this child mine." With the birth of an unexpected rookie Papa, the Demon Realm immediately fell into a Great Panic! Naming the baby Lilith, the Demon King abandoned his work, exclaiming "She's too cuuuute~!", and spent every day doting on her. Whenever Lilith just cried, his subordinates would have to run around the castle, treating it as an emergency... Can the Demon King, who doesn't even know how to feed Milk, successfully raise the baby!? A world-encompassing child-rearing journey begins, with both the Demon King and his subordinates in a total tizzy!