An astromer named Kakeru witnesses a comet around the moon which releases a crystal that he finds, unaware the comet is the avatar of malicious snow witch Princess Snow Kaguya. As Usagi, Chibi-Usa, and the other Sailor Guardians enjoy their winter break, Luna finds herself having caught a cold. As Luna attempts to go home she collapses and is nearly killed by a car but is rescued by Kakeru who also nurses her back to health. Luna develops feelings of unrequited love not only due to being a cat, but also Kakeru's estranged girlfriend Himeko who finds it challenging to stay by him due to his ridiculed theories of a kingdom having once been on the moon. Unbeknownst to Kakeru, the crystal he recovered is draining his energy and is being sought after by Princess Snow Kaguya for her ultimate plan of freezing the entire Earth into silence.
While Sailor Moon R: The Movie was successful, Sailor Moon creator, Naoko Takeuchi was reportedly dissatisfied with the end result of R: The Movie and took a much more involved approach to the follow-up Sailor Moon S: The Movie, basing the premise upon her side story written for the manga and Takeuchi even traveled to Kennedy Space Center to watch the launch of space shuttle Columbia as part of her research. Takeuchi was reportedly far more please with the end result of Sailor Moon S: The Movie, and rightly so because it does everything Sailor Moon R: The Movie tried to do, but so much better.
What makes Sailor Moon S: The Movie work so well is in its emotional core of Luna's love for Kakeru. The scenes where she falls for Kakeru are engrossing and when Luna frets over Kakeru's deteriorating health it's quite heart wrenching. There's both a sweetness and element of heartbreak to the story that strikes all the right notes as the movie and the audience know this is a love that can never be and it's handled very well with both the highs and the lows eliciting that emotional resonance that was missing (or at best very diluted) from the previous film. Much like Sailor Moon R: The Movie this is a standalone story that doesn't require in depth knowledge to enjoy it, but unlike Sailor Moon R: The Movie it doesn't seem like it has the same continuity gaffes as that film (except maybe the Outer Guardians, but they're not front and center so it's forgivable).
The action is still on point, keeping the visual polish from the previous film, but also making the stakes more heavy and global with Princess Snow Kaguya's plan to freeze the Earth treated with more urgency and investment. I think that this is a really strong showcase of all the best aspects of Sailor Moon with the romantic aspects, action, and even the humor (particularly a scene involving a Santa Claus display) being very much on point.
Sailor Moon S: The Movie is a welcome addition to the franchise being a strong self-contained story that plays to its strengths. With emotional weight from Luna's relationship with Kakeru and suitably heavy stakes from Princess Snow Kaguya, there's something that pretty much every Sailor Moon fan will be able to appreciate be they franchise veterans from the syndicated Dic dub or franchise newcomers spoiled by Viz.
