Some said that it was just a legend.
Some said that that blood has died.
Yet, they are still some that seek the one for that great immense power.
Yukiko Tomaru, is the one that born with the power to control and destroy the powers of rainbow that had been passing down from generation to generation.
She is a nobody seeking to find the truth behind her power and that special blood of hers. This power has a curse. She, due to the curse, is not being able to live longer than 27, might lose her mind if the power overtaken her.
Hiding from place to place, she reached Namimori and met Tsuna and friends. From there on, the truth slowly comes to light. Will she able to break the curse with their help or to bring them more harm?