Super Deduction and Super Luck

Ranpo puts on his glasses: Super Deduction.

Shikawa snaps her fingers: Super Luck.

Shikawa Enoshima has the "Ultimate Lucky Student" talent. So it's perfectly normal, and a cause for celebration, when she runs into her childhood fiancé on the street after eight years apart: Lord Ranpo, now one of the five executives of the Port Mafia.

Shikawa wants to be happy forever!

So "luck" made her move away from Ranpo when she was ten and he was almost fourteen.

Shikawa wants to be with Ranpo!

So "luck" brought her to Yokohama on her eighteenth birthday.

The Port Mafia members have noticed that ever since Lord Ranpo got together with the girl called Shikawa, everyone seems blessed by the goddess of luck. In every shootout, they somehow run into masters of the near miss: lucky!

Boss Mori has noticed that ever since Shikawa joined the Port Mafia, the organization has been making spectacular progress. It looks set not only to become Japan's top criminal syndicate, but also to make him prime minister: No, I don't want that!

Executive Dazai has noticed that ever since he met Shikawa, he finally managed to kill himself: Hooray! [Memorial portrait]

Lord Ranpo has noticed... No, Lord Ranpo sees that whenever he and Shikawa are apart for even a little while, his future is filled with murderous intent.

Shikawa (bashful): Will Ranpo always love Shikawa and stay with Shikawa?

Ranpo (instant reply): I'll love Shikawa forever and stay with her forever.

Shikawa (covering her face): Ranpo answered so quickly. Were you that eager?

Ranpo (smiling): [If I don't answer fast, your "luck" is going to kill me]

Today, "luck" is working itself to the bone for Shikawa again :)

The heroine is an ordinary person with luck on par with a special ability. Things always go her way and danger turns to safety. She wins every raffle and never has to wait in line when shopping [not really]. She's a bit of a sweet, naive girl, with a yandere, love-addled streak.

A child favored by luck, Shikawa doesn't have the words "unhappy" in her world. You could say she has no idea how hard life can be.

Everyday life and romance, with a side of rehabilitating the dark, black-cat Ranpo and delivering him to the President.

Note:

1. Out of character characterization.

2. Lots of personal worldbuilding.

Premise: Build a harmonious society through deduction and love.