Let's start with the most obvious one: The main promo image of "Last Friends" looks very familiar. In Bishoujo Senshi Sailor Moon Artbook IV, there is an image with a very similar concept of having the characters laying there, tied together by ribbons.

The characters of Ruka & Michiru are very similar to Haruka (Sailor Uranus) & Michiru (Sailor Neptune). This pose in the opening of "Last Friends" look very similar to the pose on the covers of Sailor Moon laser discs.

This close up shot of Ruka & Michiru is found similar to many popular Haruka & Michiru doujinshi. Particularly the ones drawn by the super popular Studio Canopus and Twin Fizz above. And if you think that maybe a doujinshi cover isn't "official" enough, please take a look at the image of Utena and Anthy from the Revolutionary Girl Utena soundtrack cover. Utena is another "implied lesbian theme" anime, whose director & writer (Kunihiko Ikuhara) worked on "Sailor Moon" as well! ^___^

One of the more obvious similarities, is that Ruka of "Last Friends" is into the sport of motocross, just like Haruka of "Sailor Moon!" And they're both really good at it. In the anime, Haruka gets harassed by a bunch of male racers ('cuz of her gender), after beating them at motocross. Haruka takes care of the problem by kicking their butts. ^__^ Its noticed that Ruka in "Last Friends" was sexually harassed by her coach. Therefore, she taught him a lesson too. (Edit added by queennepy) -- Also, Sailor Uranus's uniform in "Sailor Moon" is blue & gold. Haruka's bike is also blue and gold. We should note, that Ruka's bike is blue, and her racing gear is blue and yellow-gold.

In "Last Friends," after being abused by her boyfriend, Michiru runs away and escapes to a spot where she and Ruka used to claim as their "spot." This "spot" has a lot of seats and a little stage in the background. It brought back the scene in "Sailor Moon," where Haruka watched Michiru practice her violin at this little "spot," where there are a lot of seats and a stage. A nice little "spot" outdoors.

Even when injured and in bed, Ruka still looks amazingly charming in her nice blue PJ's. When Haruka was sick in the "Sailor Moon SuperS Special," it didn't stop her from flirting with the maid. She had on blue PJ's too!

Michiru's jacket, please meet Michiru's jacket. =D The two have similar taste in clothing too!
Not to mention similar hair styles as well.

Mizushima Takeru-- hair and make-up stylist of "Last Friends," please meet Usui Yoshiki -- fashion designer of "Sailor Moon SuperS."

On the first episode of "Last Friends," Michiru is shown at the ocean. Without background music, just listening to the sound of the waves and seagulls. This beginning is very similar to Episode 110 of "Sailor Moon," where Michiru was listening to the ocean through a sea shell. The current episodes of "Last Friends" starts out each scene with Michiru at the ocean. It draws a good comparison to Michiru in "Sailor Moon," who closely relates herself to the sea.

Aside from superficial similarities, there is no doubt that Ruka's personality is very similar to Haruka's personality. In Episode 1 of "Last Friends," Ruka has a moment where her thoughts are expressed about herself and about Michiru. Compare it to Episode 106 of "Sailor Moon," where Haruka's thoughts are expressed about herself and about Michiru. Its very much alike! *___* (Oddly, in both scenes, Ruka and Haruka are both wearing a black and white shirt!)

Ruka's thoughts in "Last Friends":

Michiru,

You said it before, didn't you.

I was by myself standing on the side,

and only following my own road.

That's wrong! I'm just scared, of people.

Even now, I can't say,

the most important thing in my heart,

I haven't said it to anyone. Not anyone.

Michiru, not even to you.

Michiru, you probably can't imagine,

how surprised I was to see you after four years.

How much I thought about you,

and wanted to see you during those four years.

And just as much, I was afraid of a reunion.

Haruka's thoughts in "Sailor Moon":

Back then, I wanted to become the wind.

I just wanted to be like the wind.

Wrestling free from the domination of gravity.

And plunging forth into the vast reaches of the sky.

That was the kind of person I wanted to be.

If I think about it, back then...

I was merely fighting to escape from my destiny.

No matter when it was, what I won from my battles.

Were all new parts of myself.

I was just running to keep myself from being bored.

In the end, the only thing that kept my interest was motor sports.

If I had not met Michiru Kaioh back then...

That was when I realized...

That she was THAT person.

And that she knew exactly who I was.

But in my heart, I didn't want to acknowledge that fact yet.

Because I had a hunch that if I did,

I was pretty sure that everything around me would change.

I'm not honest at all.

I keep running away.

So I chose this path,

I am not allowed to stand in one place.

But, I'm glad I was able to meet you...

Let's cruise together like this forever.

I won't let you go home tonight.