My interpretation of what the relationship between Zoro and his son would be like. c:!
(Kazuki means shine or hope).
Roronoa Kazuki: The son of the infamous Roronoa Zoro and Nico Robin, stood by the countless shelves he never seemed to get tired of scanning. His mother sat across from him, completely engrossed in a book he'd kindly picked out for her. With a sigh, he finally decided on what to read and settled next to her.
"Mom," he said, fiddling with his black hair. She looked up from her book.
Kazuki had a strange sense of formality towards everyone he knew. He never called his parents "Mommy" or "Daddy", even as a child. He always introduced himself before speaking to strangers. Quite the opposite of his father, in fact. It also isn't unusual for him to communicate with the rest of the crew by referring to them as Miss Nami, Chef Sanji, and Captain Luffy.
"I've been reading a lot of swordsmanship books," he informed his mother as he pointed at about a dozen books that were piled neatly on a side table, "and I've come to the conclusion that I don't wanna be a swordsman like dad."
Robin flashed her son a smile. "That's perfectly fine, dear."
"No, mom, it isn't fine," he said, his voice rising ever so slightly.
He caught himself. A look of frustration was etched on his young face.
"I get this feeling dad wants me to be," he admitted. His mom was quiet for a moment before shutting her book, not bothering to see what page she'd stopped on.
She looked at her son, whose eyes were as blue as her own, but as sharp as his father's. She didn't find it difficult at all to imagine her son as a swordsman. It was quite easy, truthfully. She tried to think back on what might've gotten that idea in her son's head.
"And…" he whispered, interrupting her line of thoughts. He seemed a bit nervous. "I feel really distant from him."
Robin's eyes softened. As a matter of fact, she knew very well how he was feeling. Zoro was never the type of man to show affection or acceptance very easily.
"Kazuki," she began with a tone that meant they were about to start a long talk. "When you were first born, the entire crew marveled at how adorable you were. Zoro, though, didn't. He simply stood by me and stared at you. He wasn't laughing like everyone else was, but his face didn't have that frown he constantly wore. And that may not seem like much, but it is. It's clear you haven't noticed, Kazuki, but each time you appear on the deck where he usually naps, his frown immediately dissolves. You're a source of comfort to him."
Kazuki turned his head away from his mother. It came out as a mumble, but Robin was able to hear it. "But why doesn't he…ever…"
His voice trailed off. Even though he didn't finish what he was saying, Robin had an idea what it was he wanted to say. She turned her gaze towards the library door.
"Give me a moment," she said, getting up and setting her book down. She walked towards the door. Once she stepped out, she saw her beloved sitting against the railing, right across from the library door. He had a troubled look on his face.
Quietly, she closed the door of the library and walked towards him. She gently pushed over his katanas and sat by his side.
"I have a feeling you heard the conversation," she said, breaking the silence. He replied with a slight nod. Getting up, he walked towards the library he barely spent time in. In truth, he felt it was Robin and Kazuki's space. He opened the door softly and stepped in.
"Oh, welcome ba-" Kazuki began, but paused once he noticed the muscular figure that stood in front of the door.
Zoro closed the door behind him and took long, slow steps towards his son. Once he crossed the library and reached him, he took a moment to simply look at the boy he was proud to call his own.
The expression Kazuki wore as he looked at his father showed both confusion and anticipation.
Zoro untied the black bandana that always rested on his left arm, then gently tied it around his son's head. He smiled. "You can be whatever you wanna be, Kazuki. That's what I want."