Volume 3 is the third volume of Fruits Basket.
As Yuki and Kyo race each other during a long-distance run for P.E., cousin Hatsuharu Sohma stops them to challenge Kyo to a fight. During the battle, Yuki has a bronchial attack, and Hatsuharu uses Tohru to transform into an ox to carry Yuki home. He tells Tohru that Yuki and Kyo have changed, in that they fight less viciously and Yuki now smiles. For Valentine's Day, Kagura forces Kyo to go on a date, which Shigure turns into a double-date with Yuki and Tohru, to Kyo's intense annoyance.
Tohru tells Kyo that while she wishes he and Yuki got along, it is okay to hate his rival. When Shigure delivers Tohru's valentine chocolate to Hatori, he accuses Shigure of using Tohru as a pawn, without concern for whether she gets hurt. For White Day, Momiji gives Tohru a trip to the Sohma onsen, and to please her Yuki and Kyo go along. While there, Tohru meets the mother of Ritsu mother Sohma, another zodiac member.
When Tohru makes an attempt to play table tennis, Yuki laughs for the first time in a long time. That night, Yuki gives Tohru a hair ribbon as his return gift. On the way home, Tohru is surprised to find out that Momiji is the same age as Hatsuharu (just one year younger)!