In a world very much like our own, great race horses of the past have a chance to be reborn as "horse girls"—girls with the ears and tails of horses as well as their speed and endurance. The best of these horse girls go to train at Tokyo's Tracen Academy, hopefully moving on to fame and fortune as both racers and idols. Special Week, a high school horse girl from the countryside, has just transferred to Tracen, and she's determined to fulfill her promise to her mother to become the best horse girl in Japan. On her way to school, she takes a pit stop at the race track and instantly falls in love with Silence Suzuka's style, becoming determined to race on the same team as her.
Episodes
Kitasan Black hopes to duplicate Tokai Teio's feat of winning the Japanese Derby after coming in third at the Satsukishou. But the Japanese Derby's course layout doesn't support her strengths as a racer...
Kitasan Black is down in the dumps over her poor showing in the Japanese Derby, especially when compared to the star horse girl Duramente. Her dream of being like her idol Tokai Teio seems farther away than ever.
The time has come for the public to vote for the horse girls that will participate in the Arima Kinen, and Kitasan Black stands a good chance of making the cut. Everyone talks about their plans for the future while celebrating Satono Diamond's debut.
Kitasan Black is stuck in a losing streak. While talking to Nice Nature, she gets the idea to attempt a more intensive training regimen, since she's not prone to injury. Trainer isn't convinced that's such a good idea...
Satono Diamond runs in the Japanese Derby, the race coming down to a photo finish. Meanwhile, Kitasan's times are better than ever after her intense training session. But Kitasan's hopes might be dashed by Duramente's recovery...
Everyone seems to think Satono Diamond can't win the Kikkashou because of the jinx on Satono horse girls. She decides to face the jinx head-on and prove there's nothing stopping Satono horse girls from winning Triple Crown races.
Kitasan Black is on a winning streak heading into this year's Arima Kinen. Satono Diamond, having "broken" the jinx on Satono horse girls, is determined to win the Arima Kinen next and so prove that she is stronger than Kitasan.
With the Arima Kinen over, Kitasan Black tries to come to terms with the outcome. She tries talking through her feelings with other horse girls, and learns about the dreams that Satono Diamond and Duramente are pursuing.
Her focus renewed, Kitasan Black's performance in races is improving. She asks Satono Diamond to go on a trip with her. After playing rock-paper-scissors to select their destination, the two go on a long train trip together.
Tracen Academy and the nearby town are holding a festival together, and the school has asked Kitasan Black to head up the committee.The festival is a great success, prompting her to think about running the Prix de l'Arc de Triomphe.
Kitasan Black resumes training, but she's still troubled by how she felt at the end of the Takarazuka Kinen. She throws herself into practice, but Trainer has started to suspect something about her might have changed.
Kitasan Black holds a press conference to announce that she will retire after this year's Japan Cup and Arima Kinen, shocking both her fans and friends who didn't know about her decline in conditioning.
Kitasan Black furiously trains for her last Arima Kinen. Team Spica together works to fulfill her final request for the race. Anticipation builds across Japan as fans realize this will be their last chance to see Kitasan Black run in the Twinkle Series.
