In all seriousness, when I found in Kodansha's Twitter that Mashima is looking for love in his next work, I couldn't help but think that he's going to remake SM manga, just because there are lots of romance in it and overall, it has the same feel as his works. Just to assure my guess, there are some links/evidences between SM and his works (Rave and FT), despite the screaming differences between them.
1st Evidence ~ Did you see that pattern?: In FT, there are some characters that surprisingly resemble some of SM's Sailor Scouts, mainly in power.
- Sailor Moon => Either Sting Eucliffe or Mavis Vermillion: Sailor Moon shares a similar appearance and powers with Sting Eucliffe, considering that her attacks are holy light based, however, if I take in account the Silver Crystal as an unlimited power source, then I'd rather compare her to Mavis, due to Fairy Heart having a similar description.
- Sailor Mercury => Gray Fullbuster: In SM's Fandom, Sailor Mercury's powers are more Ice based than Water, despite having Water elemental attacks. And thanks to that there are some crossover fanfics that focus on them. This similarity can be more obvious if we take in account the fact that Gray shares two Unison Raids with Juvia, a Water elemental mage.
- Sailor Mars => Natsu Dragneel: Both of them possess fire powers and are short-tempered people. That's quite obvious.
- Sailor Jupiter => Laxus Dreyar: Both are lightning elemental and are really, REALLY strong physically. Another obvious one.
- Sailor Venus => Gajeel Redfox (The beauty and the beast): Despite Venus being the "Yang" (light and metal) and Gajeel being the "Yin" (dark and metal), their similarity become strong when take in account the Crystal version of Venus, which is more metal based than light based, power-wise.
- Sailor Uranus => Jellal Fernandes: Gotta praise the heavens! The Heavenly Body Magic is what links him with Sailor Uranus "The Distant Heavenly King" with outer space themed attacks.
- Sailor Neptune => Juvia Lockser: Is there any need to explain?
- Sailor Pluto => Ultear Milkovich: "Time-Space Continuum" is the keyword.
- Sailor Saturn => Zeref Dragneel: Both have "Death Magic" as their power, granting OP status. Zeref can even break the 4th wall and Saturn can insta-grow into a teenager!
- Sailor Galaxia => Acnologia: Both of them are OP as well as Saturn/Zeref, have an unknown element attribute, and their goal is to kill every one of the same kind as them. Not to mention their titles.
2nd Evidence ~ Rave characters = SM villains?: Very ambiguous/inaccurate, isn't it? Let me explain. Have you seen the early designs of Haru, Shuda and Reina? They share a similar appearance of Demando, Rubeus and Esmeraude, three of the Black Moon Arc's villains of SM, respectively! Truly a case of anime doppelgangers/twins separated at birth.
3rd Evidence ~ Have Fukuro watched/read SM?: In FT, one of the quotes of Fukuro, one of ToH Arc's villains, is "In the name of justice, I'll punish you!" which parallels Sailor Moon's punch-line "In the name of moon, I'll punish you!"... And he says it while doing Venus' pose.
4th Evidence ~ Has Hiro been inspired by Naoko before making his own stories, and didn't he tell anyone?: This similarity is more technical than artistic. Rave is close to the dark fantasy concept, while FT is basically a cluster of different arcs with little to no connection between them, not to mention that Natsu sometimes goes commando, finishing enemies in one blow (also known as one-shot). For me, Rave has inherited the darkness of SM arcs and FT has inherited the PoF, Natsu's exaggerate protagonism and one shots (paralleling Sailor Moon's), Lucy's hopelessness (paralleling Mamoru's), story structure, ****** fanservice(believe it or not!), and many more things, making FT more close to SM in overall (if not a "genderbent" version of this series, technically). Not to tell that the whole Exceed thing has been inspired in SM's Moon Cats, too.