Call her and meet in person.

The key thing here is speed. If you can make sure you have an eye on her than the rest will be much easier. If Lucy is a program user than she won't have trouble accepting that her bodyguards won't be any help against demons or other users. If not, it will be a problem. At the very least, she has money. Enough to afford to keep a few goons standing by her driver's car at the end of school day. They will be easily ripped to shreds but might at least be useful warm bodies to throw at the enemy.

The phone rings about three and a half times before she picks up. "Bonjour Keito. Is there a reason you must you interrupt my busy schedule?" Trying to go over all of this on the phone seems like it would be a mess.

"Lu-Lu! Where are you now?"

"....are you ever going to stop calling me that? And, I'm in the hallway waiting for Chemistry class. Where are YOU, if not waiting for class?" That should be fine. Whatever move they are going to do, it's doubtful it will be in broad daylight with an entire class of students to witness it. No doubt they would probably destroy whoever is dumb enough to get in the way, but these aren't just rogue bloodthirsty type demons. They're supposed to be smart. They aren't going to make a body count and draw pointless attention.

"Lu-Lu. I was wondering what you were gonna do after school. Know that arcade that nobody likes because all the games are a rip-off? Wanna go do that after class?" Somehow you can hear the silence consideration across the phone.

"You won't quit bugging me until I agree, will you?"

"Nope. I really, really want to see your face today."

".......ugh...idiot. Fine. But you must only ever use my number in emergencies from now on. I have very important contacts that I need to keep this phone unoccupied for."

"Kay, see ya!"

After ending the call, the rest of the day proceeds as normal. Your classes are boring to say the least and impossible to focus on with everything else going on in your mind. When time finally comes for the bell, you have your stuff ready to leave. Sure enough, as they are right on schedule the car waiting for Lucy is out front.

She stands in the courtyard waiting and looking more annoyed by the second. "We will go out with just the two of us ONCE. You WILL be upstanding and gentlemanly the entire time." All you can do is just let out a practiced laugh of amusement. "I'd be anything you want me to be."

"..stupid. Why did you even pick the arcade anyway? Are there even any new games there?" Her question makes it seem like the best time to act surprised. "I dunno how much it's changed since the last time I was there...but....did you see this awesome new phone game yet?" Showing your cellphone to her, you know there is going to be one of two reactions.

Either she recognizes what it is and explaining the situation is way easier. If she doesn't understand what this is then you would need to keep oblivious to everything around her. Which is another challenge. She's not stupid. She is also really stubborn. If she gets suspicious then she will have to keep digging until she can find an answer.

As her eyes finish looking at her phone, her mouth moves open to say something.