Super Sailor Mercury

Super Sailor Mercury [secretly] likes Taiki Kou (Sailor Star Maker). And Taiki likes her back.

Super Sailor Venus

Super Sailor Venus likes Yaten Kou (Sailor Star Healer). Yaten secretly seems to like her back.

Sailor Star Fighter

Sailor Star Fighter likes Usagi Tsukino (Sailor Moon, THE PROTAGONIST). Usagi has mixed emotions for Seiya.

Sailor Uranus & Sailor Neptune

Sailor Uranus and Neptune are lesbians and they are dating in the Japanese version, but in the English version, they are cousins.

Sailor Pluto

In the manga version, Sailor Pluto liked Tuxedo Kamen (Mamoru Chiba). In anime, they have no relationship.