Chikane and Himeko have been best friends and together for a long time, and that day on a hill, a promise was made. A promise between two hearts, with the blue flowers as witnesses...but Chikane believes her feelings might break the promise she made that day, and change their relationship forever...

AU. Born as twin sisters, but maybe not so sisterly after all...Chikane has been working hard, but Himeko has developed...a peculiar illness. What is causing it? Why does it hurt her so much for them to be apart? Only Chikane relieves the pain she feels inside... Wincest. Updates are unscheduled, but assured till the end.