Susuki Shinichi is a guy with no unique qualities and whose daily routine frustrates him. He puts his name under a romance novel club at his school, but in reality, he doesn't associate himself with any club. He has a complex about being stuck in the background and ignored by his childhood friend-turned-class idol, Miyuki.

Spring. After the death of his father left him without any living relatives, Kusanagi Naoya is put under the care of his friend's family. There, his homeroom teacher awaits him. And with the arrival of the new school term, his childhood friend who transferred long ago reappears right before him.

Runaway City tells the story of Hiroaki, a boy with a mysterious power of Good Luck. It's almost as it some power makes women do whatever he wants. At first it's a great power to have, then as time goes by it scares him more and more. Unchecked, this power will be the destruction of all Japan.