How Haruka Became Her Excellency, Dark Haruka

I guess it's iM@S history time.

So way back in the day, when ArcadeM@S was the hot new thing, in much the same way that we'd dubbed Ritsuko "Ricchan," Haruka was lovingly referred to as "Harukakka" (はるかっか) for really no reason at all. We liked it, and it stuck; things were simpler then.

Eventually, however, as people began to tune into various relevant radio broadcasts and internet shows, listeners came to realize various things about Nakamura Eriko (Haruka's seiyuu, of course) that more ardent fans of hers had already known for the longest time: for example, she's got an uncannily absolute charisma when it comes to dealing with fans, colleagues and coworkers, she's hilariously blunt when it comes to issues of money and material influence, and she makes the most horrifyingly egotistical slips of the tongue imaginable. (It's hard to understand quite what that means without experiencing it for yourself; I'll translate the relevant videos sometime.)
As these listeners came to recognize and learned to love these more interesting aspects of her character, people began to whisper, "Heh, Haruka's actually... kind of dark, isn't she?"
With time, these sentiments began to fester and spread amongst certain members of the community, and that innocent little pet-name began a definitive transition from "はるかっか" to "春閣下"——identical in pronunciation, but all-too-different in meaning. "HaruKAKKA," or "Haruka, Her Excellency."

Nakamura-sensei herself was privy to this phenomenon, much to her dismay. To her credit, she tried her best to defuse it, but unfortunately for her, there's another part of her personality that becomes relevant at this point: her ability to inadvertently dig herself deeper and deeper into embarrassingly cringe-worthy situations is LEGENDARY.

"I'm the Dark Haruka," she'd insist. "Haruka herself is pure! Completely pure!"
When asked about her goal in sputtering these things left and right, "To not make trouble for one of the characters I play!"

In much the same vein as the "old hag" jokes that we enjoyed throwing Azusa's way, so it was that we were embroiled in teasing and hassling Haruka, Her Excellency——but all in good fun. Just an inside joke filled with love, nothing more than the name.
But in time, iM@S took off and began to grow in popularity at a startling rate (this was the age of "Tokachitsukuchite," the KOTOKO Princess Bride video, and the Golden Age of Relations); and with it, the nature of the meme began to change.

Probably because the Xbox 360 had become so difficult to commit oneself to in Japan, an overwhelming majority of the users embroiled in iDOLM@STER's popularity in the early days of Nico Nico Douga had never actually played the game for themselves.
And if you've ever actually played the game for yourself, you'll know that Haruka's real appeal is a subtle one; it comes across to some in the anime, but that's admittedly just because she gets a lot of the major development——it's really in the details of the game's events where she comes across fully.
But these users didn't know that; they only understood the most superficial aspects of each character, knowing little of the community that had heretofore taken shape. It was in this environment that Haruka, Ritsuko and Iori in particular suffered particularly harsh treatment.

Of the three, Haruka was mocked to no end as being plain, as being ordinary, with no real personality to speak of.

It was here, naturally, that Dark Haruka, Her Excellency, was born in full. A number of videos became the turning point in restoring Haruka to her throne as the franchise's keystone; videos that took advantage of the katana prop that was to become her characteristic tool, the narrowed mid-blink eyes that became the constant reminder of her presence, the Punkish Gothic costume that was to become her strongest association, the ののワ that had already become her universal signature.

In that sense, an old in-joke was appropriated from a previous age and polished anew to furnish its subject with a more potent, more direct and easily-understood appeal than that of the more properly-developed Amami Haruka we know today——one that resonated unusually well with the character of its bizarrely-eager audience on Nico Nico Douga, of subservience and worship.

An idol, if you will.

From there, Live 4 You! brought with it her new official character song, "I Wish"——its subject matter and unusually harsh tone were entirely too convenient for assimilation into the core of Her Excellency's identity, which ultimately bled over into every corner of Haruka's popularity to some extent.

The rest is plain to see, really.
Even in this day and age, with a more polished, finely-developed iDOLM@STER, you can see these elements defining Haruka's character in a myriad fanworks both artistic and whimsical in nature——deviousness, craftiness, unbridled confidence.

Impact.