Sailor Moon is one of the most beloved and iconic animes ever to exist. It has spawned several dubs, new series, movies, a musical, toys, and more. It was a saga to rock a generation.
One of the most iconic parts of Sailor Moon is the ultimate pairing of Sailor Moon herself and Tuxedo Mask, her prince and partner in love and heroism. Beyond their alter egos, these characters are known as Usagi and Mamoru in the versions from Japan, and Serena and Darien in the English versions. They are a power couple for the ages.
Relationships in general are a very important part of the series, exemplifying the bonds between people and what they will do for love. Sailor Moon and Tuxedo Mask are the epicenter, but they are not the only ones.
Before Usagi and Mamoru, there was another relationship that the tall man partook in. Mamoru once was paired off with a different Sailor Scout: Sailor Mars (Rei Hino).
Rei and Mamoru had a lesser known and shorter-lived relationship. However, the relationship was still an important part of the Sailor Moon story.
Here are the 20 Things Only True Fans Know About Sailor Mars and Tuxedo Mask's Relationship.
20 Rei Broke Up With Mamoru For Usagi
The Sailor Scout and mysterious hero began dating before everyone in the anime got their memories back. The second everyone started to remember their pasts, Rei was faced with a dilemma.
Mamoru was her boyfriend, but he was the love of Usagi's life. Ultimately, Rei stepped back from her blossoming relationship.
Though she and Usagi bickered often, she did not want to get in the way of Usagi and Mamoru's destinies.
She had extreme respect for and loyalty to Sailor Moon, despite their combating personalities.
Rei cared for Mamoru, truly, but she knew that what he and Usagi had was stronger.
Since their relationship was already imperfect, Rei swiftly called it quits after the reveal. Mamoru and Usagi got together almost immediately and became the iconic Tuxedo Mask and Sailor Moon coupling.
19 Mamoru Wasn't That Into Her
When Mamoru and Rei dated, he became someone Rei quite liked. He was smart, rich, and fun to be with. Sailor Mars enjoyed her time with him and he was an ideal possible future husband. Rei cared a lot for their relationship.
Mamoru, however, was less interested.
While he liked Rei and appreciated her company, he was generally aloof. He cared most about school, not girls.
It's also understandable when he has a confusing alter ego that erases parts of his memory and he thinks that pieces of himself are missing.
However, it's heartbreaking to watch him switch so easily to loving Usagi with all of his heart.
Rei's just left to pick up the pieces of their doomed relationship.
18 Their Meet-Cute Went Completely Wrong
The pragmatic genius she is, Rei meticulously planned Mamoru meeting her in a cute, charming way. She figured out his walking schedule and planned to walk into him after turning a corner.
This way she could be adorable and startled and he could be convinced to go on a date with her.
This went a little astray, though, when Rei turned the corner and fell on her face.
Then Mamoru stepped on her head. He apologized but then kept on walking.
The embarrassing mistake didn't stop Rei, though. She walked back up to him and invited him to tea, saying he owed her for stepping on her head.
Mamoru agreed and their relationship grew from there. Rei's fiery spirit was what got them together, even if their meet-cute went horribly wrong.
17 They Never Dated in the Manga
In the original manga, the coupling of Rei and Mamoru never saw the light of day. Not only that, but Rei was an infamous man-hater.
She was fiercely logical and didn't place much faith in men. This stemmed from her difficult relationship with her father.
In the manga, she only ever showed interest in one man: her father's assistant, Kaidou. Her father was always distant and unreliable. Kaidou was the only person who was consistently kind to her.
When he announces another woman as his fiancé, she's devastated. In the original manga, this is the only romance she ever has.
Later, she even commits to a life of chastity. She dreams of being a priestess, after all.
The anime is the only place we see the paired Rei and Mamoru.
16 Their Relationship Never Had a Real Chance
Sailor Moon often deals in fate, destiny, past, and future. This is no different in the relationships that the anime builds.
While Rei and Mamoru enjoyed each other well enough, they were up against the destinies of Princess Serenity and Prince Endymion.
Rei was the one brave enough to approach Mamoru. She was the one going on dates with him and spending time with him one-on-one. However, fate plays a vital role in this anime, and even more, memories can be hard to forget.
The second Mamoru and Usagi remembered their past together, how they fell in love, and who they once were, poor Rei didn't stand a chance.
She was up against everything: fate, destiny, their pasts. All it amounted to was that her future was not by Mamoru's side-- he was destined to be by Usagi's.
15 Rei's Interest in Mamoru Was Superficial, But Practical
Of all of the Sailor Scouts, Sailor Mars had a huge temper, but also a logical side. She was pragmatic about her interests in Mamoru.
He was smart, reliable, and his family was well off. When looking for a good husband to tick all the boxes, Mamoru was a perfect choice.
Rei found him attractive, but it was only one part of her draw to him.
Because of her calculated reasons to be interested, Rei quickly made a move on Mamoru, which is why they began dating. Mamoru also interested Usagi, but she was too nervous to do anything.
Despite her superficial reasons, Rei did care for Mamoru and did enjoy his company. They both went on several dates and had conversations about their lives.
Her intentions were formed from selfishness, but they grew into true affection.
14 Mamoru Was Rei's First Date Ever
Mamoru was pursued by Rei, but she wasn't skilled in the ways of dating. Rei had never even had a boyfriend before. Her first date with him was her first date ever.
Rei is inspired to ask a boy on a date because of a beautiful park nearby is being torn down soon. She intends to have a romantic date there before it's gone.
However, their first date started at a tea shop right after they meet. They later end up taking the date to the park before going on a boat ride.
In true Sailor Moon fashion, though, the appearance of enemies ruins the date. Mamoru pulls away, citing a headache, in order to turn into Tuxedo Mask and Rei leaves to join her team.
The date was unorthodox, but it was just right for a Sailor Scout.
13 Tuxedo Mask Dated Sailor Mars Before Sailor Moon
Mamoru is only known to have dated two women, both powerful Sailor Scouts. However, he dated the fiery Sailor Mars before Usagi was ever on his mind.
Usagi also had a crush on Mamoru when Rei asked him out. However, Usagi was nervous and sturggled with approaching him that way. Becuase of her boldness, Rei got the upper hand and the two started dating.
Though Usagi and Mamoru are Sailor Moon's "power couple," Rei was the one brave enough to treat Mamoru as a romantic interest.
Usagi, on the other hand, continued her in-person snark wars with him, him calling her bun-head, and her keeping her feelings hidden.
This led Usagi to be very jealous when it came to Rei and Mamoru, even after their relationship ended.
12 They Dated For 23 Episodes
Rei and Mamoru didn't date for very long. It was a short-lived relationship with only a few dates. However, it is less short-lived than one might expect.
The Tuxedo Mask and Sailor Mars coupling lasted 23 episodes, which is longer than most anime subplots. Subplots normally either only last a few episodes or are building to a grand finale. Unfortunately, Rei and Mamoru's cute relationship was neither.
Each season of Sailor Moon roughly correlates to about a year, as fans have speculated. Rei and Mamoru dated 23/46 episodes.
This means that, very roughly, Sailor Mars and Tuxedo Mask casually dated for up to six months.
That's a bit more substantial than a quick, meaningless relationship.
11 Rei's Desire to Compete With Usagi Factored Into The Relationship
From the first episode of the anime, Rei and Usagi began competing. Their friendship, however loyal, was often combative.
Usagi is often dramatic and obsessive, which frustrates the fiery and straightforward Rei. Meanwhile, Rei's brutal honesty annoys the wild Usagi. Then, of course, the girls like to compete, so they feed off one another to try to one up the other.
Usagi, from very early on, makes her crush on Mamoru obvious. Rei does find him attractive and interesting, but her competitive relationship with Usagi also drives her.
Usagi wants a boyfriend, so Rei contemplates it, too-- and who would be a better boyfriend than Usagi's attractive, intelligent crush?
Rei and Usagi bicker and compete all throughout the anime, but this is one of the heights of their competitiveness.
10 Fans Did Not Approve of Their Pairing
Rei and Mamoru being a couple was a sudden and surprising addition to the anime. In the manga, men were Rei's least favorite thing. She had zero interest in romance. Yet early on in the anime, she was boy-crazy.
However, she then pairs up with Sailor Moon's one true love. It was quite a controversial writing decision.
While doomed from the start, Rei and Mamoru lasted long enough to get a lot of hate from die-hard manga fans. For the 23 episodes they dated, many people were upset about it.
Between the coupling and changing of Rei's personality, it was a lot to handle.
Even more interesting, though, is that over time they also grew a small following of people who wanted them together.
9 Rei's "Infatuation" was Actually Admiration
Rei began dating Mamoru for several superficial reasons, but as she grew closer to him, she found herself caring for him. Rei became infatuated.
When she chose to break up with him for Usagi's sake, it actually quite hurt her. She kept a necklace that he gave her closeby to cherish the love they lost.
However, as Rei aged and watched the love between Usagi and Mamoru bloom, she found herself happier about their situation. She realized that the infatuation she thought she felt for Tuxedo Mask was admiration.
She did truly care for him, but more as a brother, friend, or colleague than as a boyfriend.
Rei then only felt happiness for Sailor Moon's relationship and came to better terms with the end of her and Mamoru.
8 Mamoru Has More Than One Unexpected Relationship
Rei and Mamoru are an unexpected pairing, but Tuxedo Mask has strange love situations with another interesting character.
Long ago, back when he was Prince Endymion and Sailor Moon was Princess Serenity, there was another woman-- Queen Beryl.
While Mamoru never reciprocated her feelings, Beryl loved him so much that she was willing to destroy the world if she couldn't have him... and that's exactly what she did.
Queen Beryl does get her wish, though, one time when she brainwashes him into being her beloved, the Dark Prince Endymion. The brainwashing is imperfect, though, as he still does his best to perform his evil deeds without hurting Usagi.
Though it's short-lived and one-sided, Queen Beryl's bond with Mamoru is the root of most of their problems.
7 Rei Was Changed Because of Her Voice Actor
When fans were stunned at Rei's changes from manga to anime, writers and showrunners were looked at to explain the transformation. After all, fans knew Rei to be fiery, yes, but she was also iron-willed and pragmatic.
Overall, she was more cold and aloof. A boy-loving, Usagi-fighting, hothead Rei was a bit of a difference.
Writers attributed a lot of the changes to her voice actor. Rei's voice actor Michie Tomizawa herself did not ask for Rei to change, though.
Instead it was the director, Kunuhiko Ikuhara, who changed Rei because of Tomizawa. Ikuhara cites the fieriness of the actress to have influenced him to change Rei to be more like her.
While a divisive decision, fiery anime Rei is still a memorable character who many fans enjoy-- even if she dated Tuxedo Mask for a bit as a result.
6 Their Brief Relationship Caused Friction for Years
Rei may have ended her relationship with Mamoru for Usagi, but that didn't stop Usagi from being jealous of Rei.
In several instances, the past relationship causes friction between Rei and Usagi.
Usagi brings up the relationship as a reason not to trust Rei with Mamoru.
Though Rei did a good thing, and was only following her heart, her past relationship with Mamoru causes her more trouble than it did good. She already argues enough with Sailor Moon without her holding the relationship over her head.
Usagi even distrusts Rei enough to sneak into her home dressed as a ninja. All of this is just to ensure that she's not doing anything with Mamoru, her house-guest.
5 Mamoru Has A Type
Mamoru's two known girlfriends have more than just Sailor Moon in common. They are both much, much younger than him.
Both Rei and Usagi are about fourteen when they meet Mamoru, while Mamoru himself is seventeen. This means the middle school Rei dated a college-aged man. At the height of Usagi and Mamoru's relationship, they are sixteen and nineteen, which is less strange, but still quite a big age difference.
These are the only women Mamoru has shown any interest in, even though they are much younger than him. It has raised some concerned questions among fans.
The show does little to acknowledge the strange age gaps, but does have Usagi hide her relationship from her parents initially. She's dating a college boy, after all.
4 Rei Saw Mamoru In The Bath
Long after they dated, Mamoru spends a few nights with Rei's family at the Hikawa Shrine. This is because Rei accidentally trashes his apartment with fire extinguisher when she overdoes it worrying about a fire.
Usagi is reluctant, but Mamoru goes to stay at the shrine.
Mamoru takes a break from a college report to take a bath. Rei is on her way to do her chores and when she opens the bathroom door to do her chores, she's startled by the sight of Mamoru.
Mamoru quickly jumps into the bath to cover himself and Rei runs from the bathroom, but the damage is done.
Later, Usagi finds out about the situation. She's jealously livid, even though Rei insists she didn't want to see Tuxedo Mask like this. It's a strange episode, to say the least.
3 Rei Is The Reason Why We Know Mamoru's Name
At least in the anime, the first time we actually learn Mamoru's name is because of Rei's meddling. He'd been around the Sailor Scouts because of Usagi's crush on him and their snarky banter, but he hadn't been put in the spotlight.
Once Rei starts pursuing him, viewers get an official name for the tall, dreamy college boy: Mamoru Chibi.
Because of Rei, we start to see more of Mamoru. She's the one that integrates him into their circle of friends and marks him as an important cast member.
Rei is the reason he grows close once more to his true love, Princess Serenity, aka Sailor Moon, even if this eventually dooms her own relationship.
2 Rei Was The First To Suggest That Mamoru Was Tuxedo Mask
After her first date with him, and after fighting in the park with him, Sailor Mars was quick to suggest that Mamoru was Tuxedo Mask.
Mamoru was clueless, since he never retained his Tuxedo Mask memories, but the other Sailor Scouts also rebuffed her.
No one was suspicious about Mamoru disappearing and returning when Tuxedo Mask wasn't around.
Despite their resistance, Rei was still sure Mamoru was Tuxedo Mask. Only time would tell that she was entirely correct in her assumption.
The matching heights, hair color, and face structure helped, of course.
If only Rei got the credit she deserved once everyone found out. Granted, their past lives were a shocking thing to remember and changed their current lives forever.
1 Rei Only Wanted What Was Best For Mamoru
It was a pretty intense moment in Sailor Moon when everyone got their memories back. Rei was the one who had the hardest time with it, as her boyfriend was now her teammate's soulmate.
She eventually decided not to stand in the way of true love's destiny.
This didn't mean that Rei stopped caring, though. When Rei told Usagi that she'd give up on Mamoru, she made Usagi promise to be happy with him-- or else.
Though her love story with Tuxedo Mask was over, Rei still deeply cared about his happiness and wanted to ensure being with Sailor Moon would be the best for him.
Rei would never have another boyfriend for the rest of the series.
Can you think of any other facts about Rei and Mamoru's relationship in Sailor Moon that we might have missed? Let us know in the comments!