Disclaimer: I do not own Black Clover, or any of its associated characters and lore. That right belongs to Yūki Tabata.
In Sol's Name
After receiving the support of Charlotte Roselei, Captain of the Blue Rose Squad of Magic Knights in the Clover Kingdom, Asta was recruited into her Squad where he soon enough rose from an errand boy, as was the case for all male members at the time, into a frontline mission taker that made the Squad as a whole far less stuffy and more interconnected among all it's members, men and women alike. The Blue Rose he had the most trouble winning over, however, was Charlotte's biggest supporter with a distinct dislike for men named Sol Marron.
At the mansion that served as the Blue Roses' home, Asta and Sol were sparring one another in the courtyard with the former's Anti-Magic swordsmanship against the latter's Earth and Creation Magics. As many other Blue Roses stood by and spectated the spar, Asta decided to use the banter tactic that Charlotte taught him to make things interesting. "You know, Sol, I always found it interesting that an Earth Magic girl who hates men would have the name of a sun god."
At Asta's sentence, the spectating Blue Roses gawked in horror while Sol stood frozen for a moment which actually spooked Asta to a degree until she finally snapped. "What did you say?!" Using her Magics to summon more earth-based beings, she directed them angrily at a panicking Asta as she kept on yelling. "My full name means "Brown Soil", which is still not flattering, but it does work for a woman like me! And who are you to judge, anyway?! You're an idiot man with a girl's name for crying out!"
"I didn't mean anything by it!" Asta screamed as he dodged and sliced golem by golem. "I was just trying out that taunting thing Captain Charlotte told me about!"
Charlotte couldn't help but groan in dismay as Sol yelled out. "Char, how could you talk this idiot into mocking your own sister?!"
"I wasn't mocking you at all, Sol!" Asta cried out before saying. "You're the last person in the whole Squad I'd ever want to insult!"
"Yeah, because I'm going to pound you into a mess on the ground!" Sol retorted madly.
"No, it's because you're my favorite Blue Rose!" Asta admitted in frustration as he sliced his last golem.
Once again, all the Blue Roses, especially Sol, were stunned by Asta's words. "What?" Everyone said in bewildered unison.
Releasing a great deal of breath, Asta added with a sincere smile. "Sol, you and I are alike in so many ways. We've been through so much since I joined. I like you a lot."
While Sol stood still processing Asta's words and many of the watching Blue Roses gossiped among themselves on what sort of chemistry actually existed between them, Charlotte, inspired by the scene, finally yelped. "I'm in love with Captain Yami Sukehiro of the Black Bulls! There, I said it!"
Another awkward moment passed after the blushing Charlotte's words when many of the women in the Blue Roses began to cheer for both their Captain's honesty as well as Asta's while trading stories among themselves and their male counterparts about their love lives.
As for Sol, after finally processing what had been said, walked over to Asta and then punched him in the stomach.
"Ow!" Asta yelped in pain before Sol then grabbed him by his neck.
"That's for what you said first." She seethed with a glare before then surprising everyone by briefly kissing Asta on the lips. Letting go of him, she then said more shyly. "And that's for what you said after." She then took her leave as fast as possible as everyone stood quiet.
Blushing heavily from what happened, Asta turned to his comrades and said. "Please don't take this the wrong way, Captain, but I really don't understand women."
Relaxing somewhat, Charlotte merely shrugged and replied. "I honestly feel the same way about men in general."
All the Blue Rose Magic Knights shared a good laugh from that.
Something of a tribute to The Anti-Rose story on FanFictionNet which I hope will be continued at some point. I thought about making Asta/Sol fan art instead a while ago, but my digital drawing skills have a long way to go.