First Kiss: Finally happens in chapter 14. Partially subverted in that the readers hardly get to see it, unlike most first kiss scenes in Shoujo fiction.
Kaoru: No, it's because she's a girl. I like girls!
Important Haircut: Julia has short hair in the very last episode. Mainly, this indicates that some time has passed, but in that time Ran has disappeared, and also Julia has changed somewhat.
Not What It Looks Like: Several, though one in particular was during New Years when Saeki, pissed off at Kaoru's flirtations, ties her up and threatens to throw her out with the trash. Cue Julia and Ran walking in at that very moment and add the fact that both know Kaoru has a thing for Saeki...
Screw the Rules, I Have Money!: Averted! Even though Shizuka is a famous actress with lots of power and influence, it doesn't stop Julia from putting her in 42 joint locks.
Seme / Uke: Although the Word Of God at the end of the first volume was that the seme and uke roles in Julia/Ran dynamic are not set in stone, the former currently perceives herself as the "passive partner"... much to Saeki's concern.
Shout Out: ZLAY is a parody of the real life Japanese band GLAY.
And Ran and Julia's names are a reference to Romeo and Juliet.
Also, Ran's real name, Ran Ohtori is the name of a famous Takarazuka actress. As for her false name, Ran Asakawa... well, just google it and see.
Stalker with a Crush: Ran thinks that there is one after her in one of the subplots; Saeki is convinced Julia is one and is afraid she'll take it too far.
Also, in the final chapter we learn that while Ran was supposedly living overseas with her father, she was actually still in Japan and regularly stalking Julia.
The Stoic: When Ran first appears, she gives off this impression due to her rather sleepy look and lack of expression. This changes as the story goes on.
Tom Boy And Girly Girl: Played with, the short-haired boyish-looking Ran is the more gentle and feminine one, whereas Julia is an aggressive Kick Chick.
Tsundere: Rena acts this way towards Sera, the one she loves, with emphasis on the tsuntsun side.
At one point, Julia thinks it may be better to act more cold towards Ran during work and more friendly during free time. All she succeeds in doing is confusing Ran even more.
Unresolved Sexual Tension: What the plot revolves around. Chiefly between Julia and Ran, but also between Rena-chan and Mutsuki. Also, played with between Kaoru and Saeki: since practically the whole cast are gay, it is heavily implied that Saeki might actually be a closet lesbian and that Kaoru's lust for her might not be totally unrequited. This turns out to be a red herring, though.