In ep. 2 of season 3 of Sailor Moon Crystal, Mamoru says that the amusement park Chibi-Usa is going to is in Sankakusu, which is on reclaimed land. Later, Artemis tells Luna that there are three reclaimed sites that comprise Sankakusu: Tenohzu, Kaiohzu, and Meiohzu.
It struck me that the romanised forms of these three sites can be produced by appending "-zu" to each of the surnames of the Outer Senshi (excluding Saturn). (The civilian names of the Guardians concerned are Haruka Tenoh, Michiru Kaioh, and Setsuna Meioh.) After some experimenting with romanization schemes (
tenohzu, which is the official romanisation, does not produce useful search results, but
tenouzu produced a lead) and running some searches, I found someone who claims that these three sites have the kanji 天王洲, 海王洲, and 冥王洲 respectively. In each case, the first two characters correspond to the surnames of the Senshi that I named earlier.
Is there any in-universe reason for this correspondence between the names of the sites and these Senshi's surnames? (I might shrug away "Kaiohzu Park", which appears in ep. 7 of Sailor Moon S as a one-off coincidence, but it would be unlikely if all three names matched up by chance.)
It makes sense that Haruka and Michiru have helicopters that are named Tenohmaru and Kaiohmaru, since they own these helicopters, but it seems doubtful that they would have plots of land named after them.
Perhaps their identities are completely made-up, and the surnames came after the sites were named? (Perhaps they chose their new identities based on the names of the sites?) However, at least in Sailor Moon S, the identity "Haruka Tenoh" seems to have existed even before Haruka became Sailor Uranus (per the characterisation in the flashback of ep. 17 of Sailor Moon S), even if it makes sense that Sailor Pluto would need a new identity (not being from the present).
As an aside, with slight spoilers for Sailor Moon S:
It makes sense that Saturn is excluded. Uranus, Neptune, and Pluto consistently work together in Sailor Moon S, whereas Saturn only appears towards the end of that season. I imagine that this might also be the case in the manga and SMC. Moreover, it's clear that at least Saturn has a real-life identity that has not been falsified.