WMG: Jewelpet

The Deco Stones are actually Jewelina herself.
Judging from episodes 1 and 8, we can assume that she is Sealed Good in a Can.
  • Jossed...ish. The truth is complicated. Her body is in the statue and her soul is in Decorisky. The Deco Stones carry her will.

Jewel Land must be part of the worlds managed by the Time-Space Administration Bureau.
Maybe this way we can have one crossover episode of Happiness focusing on this. Maybe...
  • Crossover episode Jossed at least.

There's actually a way for all continuities to take place in the same universe, regardless of Word of God.
Okay, so, in Sunshine, it is shown that Jewelpets are not unique. There was that island full of Tatas and that unnamed black Jewelpet who talked to others of her kind. It is reasonable to assume that the other Jewelpets have the same thing going on. It's possible that Jeweland is much like our own world; different countries, cultures and, why not, religions, which would explain why the story of the origin of the Jewelpets is different and Jewelina has a different appearance every season (you can compare this last point to Christianism/Judaism/Islam, which are different interpretations of the same God). And different cultures and religions explains why Jewelpets of the same species would have different magical incantations. The fact that there are many of the same Jewelpet would also explain why some of the Jewelpets change personality every season.

It's possible to interpret the various continuities of Jewelpet as representative of different time-periods of this hypothetical universe (assuming that only the TV series are canon):
  • Kira Deco would be the earliest to occur; humans are very unusual and something of an anomaly in Jewel Land. Additionally, they cannot travel between Earth and Jewel Land as they please, which implies that magic hasn't reached the level of the other seasons.
  • Twinkle would happen next; now, selected humans are able to travel between Earth and Jewel Land with the express goal of learning magic. However, Jewel Land still refuses to reveal itself fully to humans.
  • First series comes next; here, Earth and Jewel Land become fully aware of each other and decide to cooperate towards aa better future for both worlds. There's also mention of a past where humans and Jewelpets used to live in harmony, before Dian's rebellion made them distrustful of each other and caused them to keep to their own worlds, with Earth eventually forgetting about Jewel Land altogether, but NOT vice-versa. This past could take place between Kira Deco and Twinkle, or after Twinkle altogether.
  • Sunshine and Happiness happen a long while after the first series, and likely at the same time, due to the similar settings. Humans and Jewelpets now live side-by-side, attend the same schools, and even have the same jobs. Travelling between the worlds is easy and habitual.

Someday, there will be Jewelpets of Jadeite, Zoisite and Kunzite.
Sanrio, please deliver. Nephrite is feeling all lonely here.

Iruka is a tentacle monster.
Episode 30 clearly shows that he's not what he seems. Sapphie's reaction suggests that under that dolphin costume is something very horrible indeed... And it would explain his year-long lusting after VA-VA-VOOM Jill Konia, which ends in marriage... Oh dear.
  • Just cause he's a tentacle monster doesn't mean he'd be bad. Or Jill wouldn't be... into that sort of thing.

Adding to the shared universe theory, Jewelina goes through a process similar to regeneration to replenish her powers.
  • The reason she is a child in Happiness is because she only recently regenerated. And the Majos in the original series are a failed regeneration that split her into four different facets of her personality. Sunshine Jewelina acts the way she did because she was near the end of this version of her.

Lollip is a cross between a Jewelpet and a Sweetspet.
Her eyes are made of lollipops, a sweet, but her body isn't detachable and edible like a Sweetspet's would be, but is instead like a Jewelpet's, furry and more like a living animal. All this can be explained by mixed ancestry. The reason she's considered a Jewelpet is because there's no precedent for pets like her.

Io and Macaronia are her parents, because why not (if it makes you more comfortable, refer to the "pets are not unique" part of the shared universe WMG).