"Kakashi-nii, I want to eat meatballs!" Three-year-old Yu.
"Okay."
"Kakashi-nii, I want to protect my forehead!" Five-year-old Yu.
"Okay."
"Kakashi, smile!" Twelve-year-old Yu.
"Okay."
"Kakashi, I want you!" Yuu, twenty-six.
"Okay... Eh~??!"
This is a story about the evolution of "brother" to...
This is also an idea left behind by a fan who has read too much. It may become a trap, so enter with caution.