MamoRei

MamoRei is the het ship between Mamoru Chiba and Rei Hino from the Sailor Moon fandom.

Canon
After meeting Tuxedo Mask, who helped Rei out when she first awakened as Sailor Mars, she develops a bit of a crush on him. She begins to suspect that Mamoru looks like Tuxedo Mask, and mentions this multiple times to Usagi, but is shut down. When put under Murid's illusion, she falls in love with Tuxedo Mask (along with Usagi) and eagerly follows him around with heart eyes. When she hears that one of the parks is going to be destroyed and paved over, she decides she should go on a date with Mamoru, because then she can say she went on a date at the park, and Mamoru is also an ideal guy. Rei asks Motoki lots of questions about Mamoru, which he finds strange, but Rei plays it off.

Rei then waits around a corner, planning to "run into" Mamoru, so he will ask her out as an apology. Instead, she trips and falls flat on her face. Mamoru accidentally steps on her head, and though he is a little freaked, he keeps walking because Rei says that she's okay. Rei runs after Mamoru, offering to take him out for tea to apologize, to which Mamoru finally agrees. Mamoru feels a little awkward, but Rei manages to convince him to go to the park with her, and the two go out on the lake in a rowboat.

Rei and Mamoru date for a while. Once Usagi and Mamoru awaken as Princess Serenity and Prince Endymion, she realizes that the two have feelings for each other and she needs to back off. She tells Usagi this, and says it's okay because she knows that it was always just a one-sided crush on her side the whole time anyway. Throughout the rest of the anime she occasionally flirts with Mamoru, but never in a romantic way.

Fanon
As Mamoru and Rei's relationship was only a temporary thing at the beginning of the anime, it is often forgotten about. Many favor Mamoru's canon relationship with Usagi instead, especially since Rei actually acknowledged it herself and Mamoru didn't seem to be invested in the relationship at all. Those who like het ships for Rei sometimes prefer Reideite or Reichirou. Many fans who read the manga were very confused at Rei's pursuit of Mamoru, and much prefer Rei's original attitude towards men from the manga. Even still, there are fans who think the two have potential together. Some even ship it using Rei's manga counterpart because she is much more mature like Mamoru, and think they would compliment each other better than Anime!Rei.

Fandom
FAN FICTION