Chapter Text
Yukio had always known that his older brother conveyed his feelings more with his tail exposed than hidden. He always used his hands while he was talking as a child so the fact his tail is the same way is unsurprising. Yet, it is still startling when his brother is particularly upset that his tail stops moving. Yukio has learned to tell when his brother is rather distressed by the lack of movement of his tail. It seems like his brother just becomes overcome with the emotion to the point he cannot move. During the interim period when his friends found out he was the son of Satan, his brother’s tail did not move as frequently as when it was still a secret. It sometimes dragged behind him or was tucked between his legs. Or worse, hidden under his clothes in shame; or some desperate way to return to the way it was before. However, the heavy feeling usually passes and his brother is back on his feet as if it never happened. Yukio does not pry when his brother his like that even though he knows he should. Something in his heart stops him.
Yukio sees that confident, determined grin with a fire in his brother’s eyes and he knows that his tail is slack yet alert behind him. His tail produces no unnecessary movement as if sensing the situation. His brother would say he is serious and run off, his tail weaving behind him like a flag in the wind. It moves so fluidly during combat yet is still so vulnerable. It does not move out of the way if an enemy reaches for it so Yukio finds it his duty to protect his brother’s back. Yukio does not have the energy to chide his brother about the exposure of his tail during combat since his brother is as stubborn as a mule. He retorts that it feels more comfortable and natural when his tail is out as opposed to keeping it tucked away. Yukio would counter that it is riskier during a fight to which his brother just dismisses it. It is a losing battle to try and protect his brother verbally so Yukio drops it.
Yukio, when he has time, watches his brother cook in the dorm kitchen. It is a magical sort of experience to see how at peace his brother is while preparing delicious food to share with his friends. His tail is still and low to the ground so as not to knock anything over but Yukio could have sworn that he saw it grab an ingredient off the table and into his brother’s hand. He questions his brother about it and he merely looks at Yukio owlishly as if he had not noticed. Yukio sighs and ushers his brother to continue. He shrugs and goes back to whisking some miscellaneous ingredient. It happens again--his brother’s tail swipes something from the counter and plops it into his open hand--and this time Yukio stays silent. He can tell his brother knows what his tail is doing and is mocking him. Yukio says nothing.