Twelve is the twelfth examinee and lover of Eleven.
Twelve has long light blue hair that he wears in a ponytail with a purple ribbon tying it back. He has two long bits of hair in the front that frame his face and curl at the ends.
He wears clothing based off of a Paso Doble dancer and matches the sort of Spanish theme of Eleven.
Twelve is a more soft spoken than Eleven, but still just as loud and boisterous when it comes to love.
He is a lover, not a fighter and is no good at physical fights.
In the anime, he is introduced for a brief moment as the examinees are getting more desperate to get the Crystal Pearl. So their attacks are getting more violent.
In the manga, he and Eleven are introduced as Love Fortune Tellers and have a crowd of people surrounding them. Eleven embarrasses Rokka by telling her that her advances have been fruitless and she's spoiled.
Eleven and Twelve reveal that they are examinees upon finding out Nina has the Crystal Pearl inside her. They attack, but it turns out Twelve is no good at physical fights. So, Eleven cheers him on, but they are defeated.
But, Eleven notices Nina is in love with both Zero and Ichi, and this leads to Eleven and Twelve asking her a few questions for an "Exciting Psychological Challenge." Which is a sort of Love Horoscope/Quiz type deal. They realize Nina is for sure in love with both Zero and Ichi at the end of the quiz and take it upon themselves to help her.
The two call their Familiar, Josephine the Cow, to come and get them and they cart Nina off to their, "Love Nest! The Lovely House!" where they give Nina a red dress with yellow polka dots and tell her the results of her quiz, which is that she's in love with Ichi but wants to marry Zero.
This upsets Nina, which leads Eleven and Twelve to put a love spell on her so that she will "rapidly make her move on the boy." Which translates to "the first boy that makes her heart pound."
Nina looks out the window and sees Zero, Ichi, San, Forte, Rokka, and Go out there coming to save her. Eleven and Twelve then drop Nina into a random room in the Lovely House to be found by one of the boys.
Later, as Nina is with Zero, who has made her heart pound, Eleven calls up Nina on the house phone and tells her that the spell gets stronger as Nina's heart pounds faster. Twelve is in the background, listening.
After than, Eleven is watching Zero and Nina walk hand-in-hand down the street through a pair of binoculars. She and Twelve are happy with the results until realizing Nina's hanging around with the wrong boy.
This leads them to enact "The Romantic ♡ First Kiss?!" plan.
They dress up like Fortune Tellers, aka their usual selves but with circular sunglasses, and ask Nina some more questions. Then, the reveal that Nina's answer determines where she'll have her first kiss with her soulmate.
They then take her to the park and push her down the stairs toward the waiting Zero and Ichi. But Eleven and Twelve's plan is foiled by both Zero and Ichi kissing Nina on the cheeks. This then leads to the spell breaking and Eleven and Twelve being shot in the sky in Team Rocket Fashion.
They are not seen again until Chapter 16 Page 11, in the four frame manga. Where it is revealed that Twelve made a cameo in Chapter 1 and Eleven gets depressed.