Ikkaku told Yumichika everything.
Since the beginning of their companionship, when Yumichika was just a sickly, gangly teenager and Ikkaku was a bloodthirsty hound, the current third seat of the 11th division would not shut up and would not shut up and would not shut up. Said man found Yumichika starving and feverish on the outskirts of district seventy-seven, clutching his tattered kimono as tightly as he could. His friend still didn't know what compelled him to pick up the shriveled, bruised body and run off to the nearest medic. There had been little compassion in his heart then; the fight, that incessant drive was what kept him alive. Anyone who couldn't keep up, in his eyes, was mere trash otherwise.
Yumichika assumed it had to do with some long lost, dormant memories of his life in the mortal world. More often than not, they drove even the hardest of hearts to acts of selflessness. And in Ikkaku, that selflessness continued throughout the entirety of his friendship with Yumichika. Whatever was Ikkaku's was his, be it food or shelter or clothes or words.
In those two weeks of agonizing recovery, the man whose name he had not known yet sat by his bedside, whispering to him anything that came to mind: stories of all his battles before, fairytales he couldn't precisely recall the endings of, or even detailing the faces of the pretty women that walked by. Yumichika could remember Ikkaku applying ointments to his wounds and feeding him scraps of meat when the medic or his wife were preoccupied. Every time he woke up, he was always there talking, giving a piece of himself to a complete stranger. Someone who might not have returned the favor, had the situation been reversed.
In his delirium, Yumichika had wondered if he could do this with everyone he met thereafter. If he could take everything they had while giving them nothing in return. It should have been a forgotten thought, but it stuck with him through the endless travels with the man who saved him, who seemed to reserve his smiles and laughs for his company alone. It stayed even as Ikkaku continued to give him everything he had. Even as he taught Yumichika how to wield a sword and fend for himself. Even as he realized just how much he had come to love and adore his fearless companion.
Yumichika wanted it all. Wanted to feel someone's soul in the palm of his hand, lift it up to his lips, and swallow whole all their energy and drive. He wanted to recall those sensations Ikkaku had stirred in him again and again. To revel in the complete and total giving of one's life to another. It was truly an ugly, ominous pull, but it remained with Yumichika nonetheless. Ikkaku should have been all Yumichika ever needed; but similar to Ikkaku's ceaseless lust for battle, his greed knew no bounds.
Ikkaku didn't know of this desire, of this obsessive need for everything and anything. While he would always be the open book in their relationship, Yumichika kept his secrets buried in the darkest corners of his heart, protecting them from the very man who had awoken them. While he gave himself away freely, Yumichika always insisted for more and found more.
To Ikkaku, Yumichika was beautiful, but he would never know just how shallow that beauty ran.
Yumichika would make sure of that.