When Rhiyaku travels to Southtown to set an old score with a man named Takuma Sakazaki, Kasumi remains in her house, waiting for his father's return. After a couple of months, he comes back with bad news: he had been defeated by the son of Takuma, Ryo Sakazaki. Kasumi then tells her father to rest up, and let it all to her. Now, Kasumi takes the Todoh name and decides to fight Ryo and anybody else in her way to avenge her father!

When Kasumi travels to Southtown, she is surprised to not see Ryo anywhere. She visits the Kyokugenryo dojo, to no avail. Losing all hopes, Kasumi goes to a bar in downtown Southtown (excuse the pun). She bids the owner for a drink, and the owner tells her that sale is restricted for females. Kasumi stands up enraged and demands her drink. The owner sees this, and admires the young woman's spirit. The host introduces herself as King, and sees in Kasumi a chance to enter the King of Fighters tournament. She invites Kasumi to the competition, with the promise that she would meet Ryo there. Kasumi gleefully accepts, but she still wants her drink...

Kasumi is then sent by King to look out for Mai, who may be wandering around with no idea of what to do. Kasumi goes and finds Mai, and attacks her to see her worth. After seeing Mai successfully dodging her attack, Kasumi laughs and tells Mai she is pretty good. She introduces herself, and as that, the Gorgeous Team of 1996 is formed!

Kasumi fights in the tournament, but when she faces Ryo, she sees that her attempts are futile. She then understands why her father lost to him. Without having nothing to do, Kasumi runs away after the tournament, and is said to be in a training journey, although everybody considers her "lost".

Having trained strictly under the orders of her father, Kasumi is anxious to return to the battle scene once again, and show Ryo how much she has improved! However, since the King of Fighters tournament was put on hold ever since the end of the battle against the Orochi clan, Kasumi's chances seemed slim. However, one day, she receives a visit by her old friend and team-mate, King, who invites her to the new King of Fighters tournament, taking place with new rules. Kasumi accepts, and she is more ready than ever to kick some major butt!

A year flies by, and Kasumi still hangs around King in hopes for another participation in the King of Fighters tournament. However, she is suddenly turned down when King tells her that she has decided to lend the Kyokugenryo Karate clan a helping hand. This increases Kasumi's fury against the Sakazaki family, but King suggests that she should go meet Mai and tell her. Kasumi thinks it's the right thing, and realizes she is just in time! Mai needed a last team member, complemented by a young school girl practicing Sumo named Hinako Shidou...and Yuri Sakazaki. Kasumi isn't very fond of the idea of teaming up with a Kyokugenryo Karate fighter, but she is ready to do anything in order to raise the Todoh name up high!

Kasumi can be a strong woman, but unfortunately, she is so stubborn and clueless she often loses track of her next opponents. Some say she inherits this from her father, but if one things' for sure, Kasumi will always fight for the honour of her family, and will defend it against anyone! She says that soon everyone will know the Todoh...not the dog!