Ami Mizuno/Sailor Mercury, a Cute Bookworm and a Shrinking Violet who tends to have a difficult time making new friends (despite being humble and gentle), is Allergic to Love, frequently blushes whenever Usagi is nice to her, and often embarrasses herself whenever she thinks out loud (usually about romance or something X-rated).
Mamoru is somewhat of a Bumbling Dad forced to deal with the antics of Usagi and the Kid from the Future, who are both fighting for his attention, but he also walked in front of traffic and fell over and supposedly went to a bar with Artemis — a cat. As Tuxedo Mask, his speeches are off-the-wall and hammy, he's melodramatic, and he has created his own merchandise (a puppet, slippers, etc.)
Outside of her Sailor Mars persona, Rei became this in the 90s anime, talking in the Third-Person Person, the frequent Gilligan Cuts of her claiming that she's the most graceful of her friends, to her falling over and embarrassing herself, and the petty squabbles that she and Usagi frequently have. In one episode, she attempts flirting with The Starlights band by talking like an ojou but it scares them off.
Minako Aino/Sailor Venus at times. Like Usagi, she's a bit of a ditz (also a Malaproper in the original anime) and an overall perky yet lovable, cheerful, and fun-loving girl who laughs at her own corny jokes even when everyone in the room is groaning.
Umino is a classic nerd with tousled hair and weird-looking glasses that engulf his face, who has a notebook full of gossip about new students. Then there's the moments that he and Naru are Sickeningly Sweethearts who are devoted to each other.
Despite being a Stern Teacher, Miss Haruna proves herself to be this by being just as boy-crazy and childlike as Usagi. Episode 2 even reveals her having Goofy Print Underwear.
Became an Establishing Character Moment for Haruka/Sailor Uranus, a hard-nosed Aloof Ally of Sailor Moon who uses brute force, when in the SuperS movie, her girlfriend Michiru/Sailor Neptune casually makes a double entendre which makes her blush. Up until this point, Haruka had been a known Handsome Lech who found amusement in flirting with many women, but it turns out that she cannot take flirting back, especially from her girlfriend. It must have made an impact because later appearances showed Michiru frequently flustering her with snarks, and then there's the adorkable moments when she and Usagi interact, which is reminiscent of a big brother trying to deal/protect his wacky, tantrum-throwing little sister.
Ail, AKA Seijuro Ginga. In his human guise, he tries to be the cool and mysterious type, but his unfamiliarity and curiosity with human behavior ultimately makes him this, such as when he is forced to wear ridiculous costumes for a fashion show and doesn't realize that he is being laughed at, or when he eats human food for the first time with Makoto. His interactions with Usagi take this even further.
