Indications within the anime:

Episode 92: Conflicting. When confronted by Minako and Usagi, Haruka replies, "Yes, but our relationship is just more than that." However, Michiru says that she is not Haruka's girlfriend. [MPEG]

Episode 106: At first, Michiru wants to ride in Haruka's car, just once, even though Haruka's a girl; she pursues Haruka fairly relentlessly [MPEG] and then confesses her attraction bluntly [MPEG].

Episode 107: Haruka displays jealousy when a little boy gives Michiru flowers. ("It's not jealousy; I just can't allow you to look at anyone else...")

SS TV special: Haruka flirts with a maid, but only until Michiru comes into the room. Embarrassment ensues at that point.

SS movie: In reaction to Vadillane's keeping children from aging, Neptune suggests that there are some things that only adults can enjoy (or that are more fun as an adult). Uranus coughs.

Episode 167: Michiru catches a falling Haruka, and comments on Haruka's candy consumption. Haruka replies, "Save the scolding for bed."

Episode 180: Haruka is most decidedly not impressed by finding Seiya in Michiru's dressing room. Once the interloper has been told to leave, Michiru asks Haruka to help undress her.

Episode 181: Michiru drags Haruka away from Usagi. Haruka complains about the roughness of said dragging: "I want you to touch me gently." "Later," replies Michiru, "when we're alone."

How some countries got around it:

France: Though female, "Frederic Tenno" disguises himself as a man in mundane form, with "Mylene Kaio" pretending to be his girlfriend in order to heighten the effect. This ceases to wash after a while.

Germany: References are not eliminated, but are rendered far more vague.

Italy: References to romantic and sexual involvement were deleted outright (explaining the passage in Kappa Magazine on the topic).