The main character of Kokoro is Hatori Hayabusa, a martial artist that has been waiting to talk to a more well-known martial artist, Daisuke Suzumiya, aka the Shadow Samurai.WhenHayabusa is called to have a meeting with him,Suzumiya attacks him and Hayabusa becomes unconcious. A few days later he finds himself in a beautiful open field, and is awakened by a young girl's voice. Hayabusa later discovers that the girl's name is Rie, and she becomes his student. Hatori Hayabusa takes Rie to his dojo to begin training her, where Rie meets Yuki, Hatori's most dedicated student. Rie and Yuki become very close and often help each other with their martial arts training. Years later Yuki recieves a letter from one of his friends saying that he is needed in a different village. When Yuki ges there he meets new martial artists, such as Ryu, Kyoko, and Shisho Daisuke Suzumiya. Yuki, contacting Hatori-sama and Rie less and less over time, becomes Suzumiya's student and decides to fight Hatori to help his new martial arts family. Rie finds out about Yuki's plan, and being dedicated to Hatori, makes it her goal to bring Yuki back and make things the way they had been for years, even if it means attacking him. Hatori and Rie sneak into the Suzumiya dojo-Rie assuming the name Sora (which she is known as for the majority of the manga)-which leads to a battle between Rie and Yuki. Rie realizes that Yuki is much stronger that her, and is saved by Hatori. There are many more battles between the two, including a fight between Hayabusa and Suzumiya. If you are interested in reading Kokoro, please contact me.