Temple of Ranma's Sailor Senshi Seifuku

No idea off the top of my head which, but I've seen at least a few where they think Tarou is one.

Meh... been busy...

Personally, never really cared for that aspect... it always seems to come across as them being trigger happy.

Now... Mars beating up Gosenkuji thinking he is possessed by the dark side, or all the ones with Happosai, or even the ones where The Senshi were hired by Kuno or Gosenkuji to take out the foul sorcerer... those were funnier. For example 'Chaos Factor' by Nemo Blank (god I loved Kodachi in that one).

Still, one immediately comes to mind to fit:

Makoto thought him one in:
R-MULTI 'Not Another SI Fic' by Enigmatic Magus-T Kagato - [Dld Date=12/20/2009] - [Dld Size=1501kb] - [Dld Files=56] - [Status=Not Complete]

• [Author1] http://www.fanfiction.net/u/100997/Taiteki_Kagato

Uranus thought he was one in:
R-SM 'All The Small Things' by Chibi-Slacker - [Dld Date=09/10/2005] - [Dld Size=499kb] - [Dld Files=11] - [Status=Inactive]

• [Direct] http://www.fanfiction.net/s/197714/1/All_the_Small_Things

Also, it was mentioned the Senshi fixated on him in one of the snippets in the Ranma Loops over at TFF...

Personally... I think it not done as often as it would seem due to the fact he would likely trounce the senshi in a fight, and many fans would not like to see them bullied... he does *not* fight* like a youma... nor act like one. I seriously doubt they could take him before he brutalizes them.

Fought them I think in:
R-SM 'festival' by genhoss - [Dld Date=04/10/2009] - [Dld Size=368kb] - [Dld Files=7] - [Status=Inactive]

• [Author1] http://www.fanfiction.net/u/1005091/genhoss

And again in:
R-SM 'Just a plan' by Poly - [Dld Date=02/06/2006] - [Dld Size=254kb] - [Dld Files=21] - [Status=Complete]

• [Direct] http://www.fanfiction.net/s/1315384/1/Just_a_plan
• [Author1] http://www.fanfiction.net/u/341477/Poly

Senshi tried interferring in a fight between Happosai and Tarou.
R-SM 'New Beginnings' by Dark Phoneix - [Dld Date=04/25/2002] - [Dld Size=69kb] - [Dld Files=2] - [Status=Inactive]

• [Author1] http://www.florestica.com/dphoneix/index.htm
• [Author2] http://www.fanfiction.net/u/60506/Dark_Phoneix

Runner up, Ranma and others thought a youma was Tarou with a new curse.
R-SM 'Heart of Fire Heart of Darkness' by Aaron Nowack - [Dld Date=07/05/2002] - [Dld Size=36kb] - [Dld Files=3] - [Status=Inactive]

• [Direct] http://www.fanfiction.net/s/264196/1/Heart_of_Fire_Heart_of_Darkness

Runner up... there was one where Aeyka in Tenchi thought he was a Youma, and another two where he was a offworld assasin (one of the 2nd type was in 'Chaos Factor'). Neither fit your search though.

Runner up... Pluto attacks him, but knows exactly what he is in:
R-SM 'Wrong Place, Wrong Time' by Innortal - [Dld Date=05/14/2006] - [Dld Size=158kb] - [Dld Files=5] - [Status=Complete]

• [Direct] http://www.fanfiction.net/s/2872057/1/Wrong_Place_Wrong_Time
• [Author1] http://www.mediaminer.org/user_info.php/115688/
• [Author2] http://www.fanfiction.net/u/681915/Innortal

Meh... there are more... but I'm not bothering.

In "Just A Plan", Ranma fought with them as Sailor Sapphire. Well, it was better than being bored to tears.

Spokavriel wrote: Well if it has a moment where any Senshi confuses any curse victim for a Youma it fits. It just has to have a moment like that somewhere in it.

Well... there was this moment in "Hotaru 1/2"...