There are alot of mistakes regarding the StarLights/Three Lights on the net. Here I explain some of the ones I've found and correct them. Hope this clears out some heads...

-Sailor Stars?- People actually call the SailorStarLights SailorStars! I believe this results as a misinterpretation and an association of the title of the 5th season of Sailormoon to the new senshi that appear on the same series. However, this is a MAJOR error. The SailorStarLights introduce themselves as so when they appear, in each episode. Therefore I think there should be no possible mistake.

-Kou?- Kou is the Three Lights LAST name. People often think it is the first due to the common sense that in Japan, last name comes first. However, for idols, if you look around in japanese magazines (such as Newtype ^^;), you may discover that in every idol article or announcement or whatever, first name comes first and last name comes last. Don't ask me why, but it is true. Therefore, I should apply the same rule to our dear band. On the other hand, wouldn't it sound real strange if they were all named Kou? A little loss of originality, ne?
Eolo also pointed out to me that they are foreigners, therefore not from Japan, because they have the furigana (the little letters on top of the kanji to know how to read it) on top of the kanji in their names as katakana (the japanese alphabet used to write foreign words), therefore indicating that they are not from Japan. Therefore, if they are not from Japan, their name is read just the same way as in all countries... first name comes first, last name comes last. An example of this is Li Shaolan from Card Captor Sakura (CLAMP). His first name is Li, and he is always introduced as Li Shaolan (even in school), because he is from Hong-Kong. He also has the furigana in the top of the kanji in his name written in katakana.

-Brothers?- The Three Lights descended to Earth under a cover, that implied the brothers thing. Otherwise, why would they all have the same last names? However, they aren't brothers... I don't even think they are brothers in Kinmoku-sei, but anyways... it just would be plain weird have twins with so different characteristics.
Naoko Takeuchi-sensei pointed out in ComiCon that the Three Lights are best friends. Just for you to know. - This info was found in The Sailor Star Lights Homepage.

-Boys or Girls?- This is one on which I can find an easy answer. On a flashback that the Three Lights have with their princess, they are transformed, and on Kinmoku-sei. Therefore I should admit that, as with the senshi, they are always transformed when in duty, therefore, always girls. The Three Lights also mention once that they came to Earth disguised as boys to find the Princess more easily. Don't ask me why. Still, I prefer to believe that they have both genders, and on Kinmoku-sei, there aren't genders. Therefore its inhabitants can have both genders.

-Vocals, Guitar, Keyboard?- In all of the pages I've seen, the Three Lights have wrong band parts. Did this people see Stars, or just plainly rip off other persons pages? I'd go for the second choice... *sigh*
Well, the fact is that in the episode where the Lights perform with Michiru in a concert, you can see their band parts: you see Seiya playing a guitar, Yaten playing the bass, and Taiki on the keyboards. On other episodes, you can see Seiya playing the drums, and Taiki playing the piano.

-Tranvestites?- Oh please. They change genders, they are absolutely NOT tranvestites.