As a child, Koizumi hadn't thought of himself as being particularly popular. That wasn't to say he thought he'd been unpopular, either - simply that he had had his own small group of friends, like many children did, and generally kept himself to himself in most other matters.
His first thought, on getting the notice that he was to transfer in order to monitor Suzumiya Haruhi, the Suzumiya Haruhi, was this has to be some sort of error. He supposed that, of those in the Organisation, he was around the right sort of age to do so and it wasn't that he had anything in particular against the idea, only that it seemed amazing that he'd been picked in the first place. It wasn't clear from the communication exactly what the role would involve, but just knowing that it involved her meant that it was, without doubt, a matter of great importance.
"You'll have to get her attention," Mori had said. "Obviously, being a transfer student will be a large part of that. Even if you're in a different class to her, that's the sort of thing that students get excited about, isn't it? Knowing there's someone new, but they're off in another room so it's a challenge to even be able to see them... you'll be fine. I'm sure of it."
She said that, but Koizumi still felt slightly at a loss. Get her attention, she'd said. Having somewhat naturally fallen into comfortable friend patterns in the past, he wasn't sure he'd ever purposefully pursued somebody like that. He couldn't fight off the thought in the back of his mind that said that turning up and almost immediately going after a girl - one girl in particular - had the potential to be read romantically, badly, or wrongly. How do you approach someone like that, anyway? It was important for the mission, but that fact only made it harder. Even making a bad first impression had the potential to sabotage his chances.
(And even then, chances for what? It was easy for them to say 'get her attention', 'get close to her', 'observe her', but those things couldn't be done in isolation. She wasn't an insect under glass, she was a living breathing human(?) being who had the potential for any number of reactions - many of them negative - on gaining his interest.)
Koizumi sat in front of where Mori stood, weighing those prospects up in his mind as she teased fingers through his hair and then stood back to look at the result. She didn't look at him as he judged her reaction - a frown. Not quite. She grabbed a hairbrush, and set about using that, instead. ...Maybe approaching Suzumiya romantically is a valid strategy? The thought was rather duplicitous, but he was going to North High essentially as a spy to begin with, so there was really no way of avoiding that. (Mori adjusted his tie, buttoned up his blazer.)
"... It's probably better if you try to be, I don't know... cool?"
"Yeah." She stood back again, looking over her work. "Smooth. Friendly, but a bit mysterious. Make people want to like you, get to know more about you." (Again, Koizumi wasn't sure he knew what to do with that, and the hesitation was clear on his face.) "Hey, it won't be that bad. Isn't that what people your age are into? A fresh start, having a blank slate to present yourself as the person you want to be..." (She patted his shoulders down.) "That sort of thing. Nobody will know the real reason you're there, so you can use that to your advantage."
"I'm still not... quite sure that I can--..."
She smiled, but Koizumi knew the steel behind those eyes. "Of course you can. They wouldn't have picked you if they thought you couldn't, right?"
I'm still not sure they made the right decision. "Mm... about that..."
Mori put her hands on her hips, still smiling. "Hey, don't go having doubts before the mission's even begun. It's not like this could have been any sort of a snap decision - they'll have made hundreds, thousands of calculations as to why you are right for this job. If you weren't the best suited for it, you wouldn't be sitting in front of me right now. I'm sure about that."
"Stand up for a moment." (He did so. She tugged his blazer down to straighten it, and pushed at him to turn around so that she could see him from all angles.) "There, I think we're done here. Just keep in mind, it's like you're on display. Sit up straight, keep your uniform tidy, be a model student. The level of study shouldn't be a problem... and I'm sure a lot of girls will be eager to help the new transfer student catch up with his work, right? Be polite. Smile a lot. Hold doors open. Carry a spare umbrella." On seeing Koizumi's expression, she lightly punched at his arm. "Koizumi-kun. You can do this! I know you can. You trust me, don't you?"
"Exactly! So you've got nothing to worry about. If everything does go wrong, I'll take full responsibility!" She winked. "But it won't, so we're good."
It's easy to be optimistic when you're not the one having to do this.
Days later, he sat in the back of the car taking him to his new North High-proximate apartment, still unable to shake those feelings. Pressing a hand to his thigh, he could feel the shape of his phone in his pocket - just knowing that it was there was a comfort. "If you need me, just call me," Mori had told him. "I'll always answer. That's why I'm here!"
The car pulled up to the apartment complex; school in the morning. This was it. Koizumi dusted himself down on leaving the car, then turned to give the driver his best smile.
(It didn't hurt to practice.)