[draconious380]

This could have been a poll, but there are just too many possible so I'm just going to pose who are your favorite secondary characters or sidekicks.  (Example: in Inuyasha, Miroku is a main character. However, he is only a secondary character since the show is mostly about Inuyasha and Kagome)

Here are my top three:

Ryuuk- Death Note

Hagi- Blood+

Sesshomaru- Inuyasha

[Warlord Vir]

Washu- Tenchi Muyo
Mihoshi- Tenchi Muyo
Urd-AMG
Skuld-AMG
Sasami-Tenchi Muyo
Ryo-ohki- Tenchi Muyo
Martina- Slayers Next
Filia- Slayers Try
Zelgadiss- Slayers
More on the way.
(Not in order of most favorite)

[rumiya]

sasami -tenchi,pretty sammy
 misao amano ,  pretty sammy
 fate teseteroisa , magical girl lyrical nanoha
 lacus clyne  , gundam seed ,destiny
 harica fuminiga  , rumbling  kiminozo hearts

[Skuld-chan]

That's easy!  (Listed in order)

1.  Skuld (Ah My Goddess)
2.  Sasami (Tenchi Universe)
3.  Kiyone (Tenchi Universe)
4.  Washu (Tenchi Universe)

[I wonder what lies beyond that...]

where is Ayeka on that list kusha?

[Warlord Vir]

I assume Ayeka is a main character or I think at least Kusha thinks so.
I personally do not know either way.

[Zionia]

Urd
Sasami
Tsunami
Kyo

[I wonder what lies beyond that...]

[q]
If we assume Ayeka to be a main character, then surely Skuld is also?

[Warlord Vir]

It depends on how you define a main character.

My thoughts are that if you remove the character and you destory the entire show, then the removed character is a main character.

Removing a secondary character would only lessen or weaken the show.

However, what I have just stated has a fine dividing line which is not alway easily visible.

To put it simply, I think Ayeka is main character(by a slim margin) because the whole show is about Tenchi, Ryoko and Ayeka and everyone else add substance to the story.

You cannot have Tenchi Muyo without Ayeka(however, it pretty hard to think of without most of the character like Sasami, Mihoshi, Washu, and etc.)

About Skuld...

WELLLLLLLLLL,

She is pretty close to the line, but the show is essentially about Keichii and Belldandy. NO Keichii and/or Belldandy = No show. However, having no Skuld is hard but not impossible.

But this is arguable stuff. I think we may need a defining rule on this by someone who understands this better. I am no expert.

[Zionia]

for once you actually have said something that makes sence WLV...that is the best way to ID the difference between main and 2ndary characters: can the story exist without them? Ayeka is keyed to many many things in the TM series..if you cut her out, the show would lose most of its plotlines and main story. Skuld however, is not an essential part to the plot of AMG, in fact many episodes she is hardly in them anyways...

[Warlord Vir]

Well, Thank you.
However, if you have seen Red Drawf. You make me out to as smart as CAT is.
And so you understand, in one episode,  Cats saids "Two good ideas in one lifetime. I am on a roll."

[Dragonchilde]

The following are true

1. Ryo-Ohki: Tenchi Muyo
2. Fu: Tenchi GXP
3. LaLaRu: Now & Then, Here & There
4. Melfina: Outlaw Star
5. Ryoga: Ranma 1/2

[draconious380]

Melfina was a main character in Outlaw Star.  Without her the whole series would have lacked a plot.

[Dragonchilde]

True, but the focal character was Gene Starwind, melfina was not that active in the series unless they were in the ship, that is, until the end.  So you can say that she started out as a secondary character and ended up as a major character. 

And remember, just because a character is not a main character does not mean the dont have a massive influence on the plot, look at most of the sub characters in tenchi, ie... Nagi, Zero, Tokemei, Kinoke, ect...

What the key is, does the anime center on telling the story of the character, ie Tenchi obviously centers on Tenchi, so the rest are just supporting characters, none of the tenchi series would have evolved at all without ryoko, considering she is the first character he meets in each, yet she only supports the telling of tenchi's story. 

This is why I consider melfina a secondary character.

[draconious380]

It is a matter of opininion but a character intergral to the plot of the entire series is not usually secondary, and I'm not gonna touch the Tenchi thing because that was disputed earlier in this post.