I do not own any of the characters used in this fic; they were created by Tsugumi Ohba and Takeshi Obata. I do not think that this disclaimer helps me legally. Anyway, enjoy this short story. I took a plot idea from an old comic book story and changed it a bit.
Light Yagami was walking past his little sister Sayu's room when he heard her voice from behind the closed door. "I sure hope Light doesn't find out what's hidden in my room, Akira," she said in her cell phone. Interested, he stopped to listen. "It's in the second drawer from the bottom. I hope he doesn't look there!" Light started walking again, quietly, to get away before Sayu had a chance to notice that he'd overheard her.
He sat down in his room and thought it over. The second drawer from the bottom. He would just have to wait until she had gone out, and then he'd make sure to see what was in there. For a moment, he worried that he might be ruining some surprise for his birthday or Christmas, but since both of those days were far away, that wasn't likely. Especially since Sayu had never given him anything for his birthday or Christmas before.
Wait a minute. Her voice had been unnaturally loud. She didn't usually speak that loudly. She must have wanted him to hear what she was saying. Yes, of course! She had prepared some kind of trap, and when he was walking by she made sure to mention the second drawer loudly to make him curious about what was there, so that he'd take a look and fall into her trap! Devious!
On the other hand... She had been speaking unnaturally loudly. Too unnaturally loudly. Not like somebody who was making a bad attempt at acting. More like somebody who was trying to sound like she was making a bad attempt at acting. Overdoing the bad acting to make sure he would notice it. She wanted to make him think she was trying to lure him into a trap! It was a clever attempt to make him suspect a trap so that he'd stay away from some secret she had there! But what kind of secrret? Good question. He'd have to look.
No! That was what Sayu was planning! She wanted him to think that the unnatural way of speaking was meant to make it seem like an attempt to make him think that he'd seen through an attempt to make him...
He kept on thinking the matter over.
Great, Sayu thought. She put down her phone, which had been turned off the entire time. Light fell for it. Messing with his head was fun, and this one would keep him thinking for at least an hour. After that, he might take a look in the second drawer from the bottom only to find that there wasn't anything special in it after all. Sayu could be clever too, when she felt like it.