All eyes are on Toukai Teiou as she takes on the Japanese Derby, ready to gallop in Symboli Rudolf's footsteps and become an undefeated Triple Crown Horse Girl. The stands are full. The track is set. It's time to see which horse girl fortune favors!

Osamu and Youko Sonoyama want more than anything to adopt every child from Soramame House, but the wealthy couple can only pick one due to their increasingly old age. While they contemplate this delicate decision, one child's alluring beauty and gentle soul instantly draw them in. Two months later, the Sonoyamas welcome 13-year-old Hitori into their warm and loving home. However, Hitori's humble and overly polite exterior is merely a masquerade. In reality, Hitori is a carefully crafted character played by identical twins Migi and Dali. For them, being the ideal child of this kind couple is merely a stepping stone to infiltrating a certain quiet town. While dutifully protecting their cover, the twins work toward their true objective: to discover the truth behind a past incident that left them with a burning desire for vengeance.

The Yuzuki family, which consists of four brothers, lost their parents two years ago. Hayato, the eldest son, is a hard worker and the pillar of the family. Mikoto, the second son, is calm and collected, but he has a soft spot for his younger brother Minato, whom he adores and thinks is cute. Minato, the third son, is energetic and adores his brothers, but he is clumsy and awkward. Gakuto, the fourth son, is a studious and mature first-grader who is often referred to as a "wise man." The manga depicts the four brothers' daily lives as they navigate their family, school, and community.

Shun Tokinoya is a second-year high school student who lives with his mother and younger sister. After his father was killed in an accident and his sister was injured, he quit the game he loved and now works at an esports café called "FOX ONE." He spends all of his time studying and working part-time, while also socializing with his childhood gaming buddies. Suddenly, he discovers that "FOX ONE" is deeply in debt. Shun and his friends hope to win the "Xaxerion Championship" and the prize money in order to repay their debts. Shun returns to the world of online games, where he is confronted by Bakuretsu-kun, who used to play the game with him.