Umika Hayami

Umika is the yellow ranger of the Lupinrangers. She also has a crush on Kuroninja, but this is not due to Kuroninja releasing pheromones in the air. Kuroninja and LupinYellow have been together since January.

History in the Kuroninja Multiverse
When Kuroninja and the Lupinrangers first met, LupinYellow fell for Kuroninja. Kuroninja, however, didn’t know what this was. He then got his heart stolen from him.

Later, Kuroninja decided to hang out with Umika (Anti-Kuroninja May have been involved with this), but then fell in love with Tsukasa, also known as Patoren3. Kuroninja, however, saved Umika from falling to her death when Darkprism forces invaded Earth-1.

Nothing much happened, until Easter 2018, when Kuroninja invited Umika to watch a movie with him. Umika thought that she was going on a date with Kuroninja, but Kuroninja was actually going on a date with Tsukasa, whose Earth-0 counterpart liked one of Kuroninja’s tweets. Kuroninja invited Umika so that nobody would think that Kuroninja was going on a date.

Sadly, on February 2019, a few days before Valentine's Day, Umika and the other Lupinrangers got trapped inside Dogranio's safe. Kuroninja decided to start dating her best friend, Shiho Ichinose, after this. It didn't last long.

Return in 2020
In 2020 Umika and the other Lupinrangers escaped from the safe and Umika reunited with Kuroninja. Now they are together since January again.

Together since January
Kuroninja will usually claim that he and LupinYellow have been together since January. Surprsingly, they have really good chemistry together, and both of them have been 1-time Gauntlet Mixed Tag Team Champions, winning against the Go-on Wings."“俺たちは1月以来一緒に. ” -Kuroninja, talking about how he and LupinYellow have been together since January"Unfortuantely, Kuroninja’s Earth-0 Counterpart likes LupinYellow because her Earth-0 counterpart used to be an idol. So maybe that’s why he supports this ship.

Since August 25, Kuroninja changed the catchphrase to "俺たちは初日以来一緒に" which loosely translates to "We have been together since day one." In 2019 he started using "俺たちは昨年以来一緒に" which means "We have been together since last year."

Trivia

 * Kuroninja actually likes Tsukasa more than Umika. It's just that the relationship between Kuroninja and the latter was more memetic so it got more attention.