@XerXes:
Only issue is that neither series is a harem series. Both series are a mix of ecchi, slice of life, comedy, and supernatural, but harem it is not because there are really only two girls actually in love with Araragi and that's Hanekawa and Senjogahara. You can throw in that, hmmm, forgot the girl's name who was possessed by the snake, but even based on how her character is written any attraction she has for Araragi isn't meant to be taken as seriously as a typical third wheel might in an actual harem title. Bakemonogatari is steeped heavilly in mystery, not romance, and his interactions with the girls stems from trying to find out what's wrong with them and finding a way to "fix" them. Nisenmonogatari, which was definitely the weaker of the two series, had more of an emphasis on comedy and fanservice but again, a harem series it was not because by the middle of the first series, Araragi and Senjougahara were already a couple. It isn't really a harem once a couple is confirmed within the story. Further proof of this can be seen in that with the exception of that girl who was possessed by the snake, no one in series two ever made a single pass at Araragi. Kanbaru's advances don't actually count as her personally in general is simply lewd.
I think you really don't understand what makes a harem series a harem series. Just because it deviates on small parts from the standart structure doesn't make it something else.
1. Harem series are in essence is stories about a single male protagonist and any number of female "protagonist"(although I'd argue that such a thing as a female protagonist within a harem story doesn't exist, they are all sidekicks really) higher than 2. This holds true for the monogatari series. It's not about the supernatural it's about araragi an the girls he helps.
2. Every female protagonist is one way or another in love with the male protagonist. Yes this is absolutely true although the kind of love is often defined really vague for the sake of playing with the audience and if especially for season 2 it's for pandering to all kind of fetishes.
Every girl in the monogatari series is in love with the male character if you don't think that is true you haven't paid attention. The toothbrush episode is a major giveaway of the nature of this show.
3. A harem series strives on the interaction of the male protagonist and his female counterparts and doesn't have any kind of overarching plot structure.This is also true. No story in the series is connected to on another and every supernatural story is just an excuse for interaction. This is a necessity for this series, or else we would have them be in the same school which is a setting done to death.
There are probably a few more harem elements that I haven't listed that hold true for the monogatari series. Really plenty enough to have it qualify as such
Heroines not making a pass at the protagonist is not unusual for harem series. I believe there exists personality archetypes for female harem protagonist that make a point of never making a pass at the lead. Also
Shinobu and Hajikuji both made passes at araragi and you discounting kanbaru based on personality is also rather wrong. Personality does not factor in as long as the action show otherwise.
Also things as the feelings between parties also don't factor in because they are more often than not in flux during those series.
It's also arguably not a slice of life series per se. The series doesn't use mundane everyday activities to entertain it makes use of supernatural elements + the relationships to entertain.
**** ****The rest to be announced in few hours….
