The moment Shinichi got back to his table with Shiho, he knew something was different.
He'd felt bad about leaving her there, but Inspector Megure had called him specifically to discuss case details for a trial. Shinichi had felt uneasy about refusing the call, and Shiho had encouraged him to take care of it, so he'd stepped away to avoid people nearby overhearing. Unfortunately, it'd taken longer than he would've liked, and by the time he returned, Shiho was already halfway through a margarita.
Shinichi would be the first to say that Shiho wasn't as cold and she might seem, and he did enjoy their relationship. They could talk about anything from the nature of knowledge to recent J-League fixtures to her intense disapproval of his hairstyle. It was that last part that seemed most emblematic of their relationship: the banter. It was fun and engaging and didn't offend him, but she was never the type to be overly affectionate.
Right away he noticed that she was different that night. She lazily traced her finger around the rim of the margarita glass, and instead of making a cutting remark about how long he'd been gone, she was distinctly more animated than usual. "Unraveling the mysteries of the world one case at a time, hm?" she said with a dreamy smile on her face. "You're really something, aren't you?"
He tried rolling with it like usual, assuming she was leading up to some brutal punchline that would keep his ego in check, but if Shiho was supposed to be a panther lying in wait, she wasn't pouncing just yet.
"I don't know why you're acting so suspicious," she said, leaning over the table in a manner that put her face quite close. "My boyfriend doesn't just fancy himself a superhero; he's constantly making it reality. Any woman would be impressed."
Shinichi had to wonder—was that her first margarita? She said she lost track. What on earth had gotten into her to let herself go so far?
That being said, it was tempting to take advantage of the situation. Just having heard her say she was impressed with him had made him wish he'd been recording the conversation. What else could he get her to say?
Of course, Shiho was still sharp enough to pick up on his efforts to steer the conversation. "You know you're clever; you don't need me to tell you that!" she insisted loudly, enough to make him worry that he needed to shush her to avoid drawing attention from other guests. "That's not your problem," she went on. "Your problem is that you insist on being suave and dramatic! You let your feelings out in bursts and then act as though they don't exist. That's not normal. There are lots of thing about you that aren't normal, but that's definitely one of the worst!"
So much for getting flattering admissions from her. Still, it was surprising. He'd never thought of himself as shutting himself off. He just had work to do and didn't need irrelevant stuff getting in the way.
"Like right now," she began. "You've taken me to dinner. Are you even having a good time?"
He was about ready to laugh. She was far more drunk than he'd ever seen her. It was intriguing because her body language was relaxed, and the way she was batting her eyes and crossing her legs could almost convince him she was thinking about skipping dinner, but even putting all that aside, he was enjoying himself. These were thoughts of hers, a side of her, that he once thought he would never see.
"Boring and ordinary, isn't it?" she remarked bitterly.
"Come on. Every time I learn something new about you, it seems like it completely changes my idea of who you are. It's fascinating."
"So I'm just another case to you—a puzzle to solve?"
He didn't feel that way. If he had, then he would've been annoyed to have her spilling all these things without him trying. Instead, he was annoyed that she was doing it because of alcohol instead of as a sober measure of trust.
"I do trust you," she said, in a more measured and considerate voice than she'd managed for the rest of dinner. "I thought I trusted you on the things that matter and that all the rest of it would figure itself out in time." She looked at her drink. "But it doesn't work that way, does it? People have to try when it comes those sorts of things."
Though he could agree with her sentiments, he still chalked it up to a little too much alcohol spurring on a bout of melancholy. For that alone, he hoped she wouldn't touch another drop all night, but Shiho still found it appropriate to order another margarita—despite Shinichi's strenuous objections to the server. She excused herself to the bathroom just as the next drink arrived, so Shinichi took the opportunity to take that drink and find somewhere to pour it out before Shiho drank any more and said something she would really regret.
But, being a detective, something was nagging at him. Just how strong was this drink to make her lose so much of her inhibition? He took a whiff of it.
And he frowned.
And he muttered something under his breath. "That woman…!"
He went right back to his table, placed the margarita next to Shiho's plate, and waited. Shiho returned, all overly-genuine smiles, and sipped her drink without batting an eye.
"You know," said Shinichi, "I think that drink might be a little weak."
"Oh, is it?" Shiho stiffened a little, sitting up straighter. "Well, that's probably for the best. On second thought, I've probably had enough."
"You have," he said.
"But I don't regret it," she went on, eyes firmly fixed on him.
"I don't, either," he said.
She smiled, and she didn't touch her drink for the rest of the night.
For CoAi Week 2018 Prompt #3 – "Poison/Alcohol"