It was never part of the plan (Usui Takumi x OC)

Suspect found!

 "Good morning, Mia!" Usui said, surprising the girl in front of him.

 "Oh hi! Did anything happen yesterday? I mean you said you'd try to pluck information out." she asked, recalling the spy that has been following the boy.

 "It was completely useless. Every time I ask him something, all he'd say is 'Nin-nin'. It seems like he has no intention at all to tell me why he's following or what they want me to do."

 "Is that so?" she asked as her eyes cast down, she was thinking.

 "Hey, Mia!" Misaki poked her nose in the conversation out of nowhere "Do you know who that guy is? He's been at the gate for quite a while, yesterday too. And what's with the ninja costume?"

 "Tourists, Misaki. They want to embrace the culture of Japan. You can see me running around cosplaying Hatsune Miku anytime." the brunette explained, patting her friend's shoulder.

 "Do you?" she asked, confused.

 "Nah, the dress is too expensive. Anyway, see you in class!" the girl waved goodbye to her friend and went to her own class.

 At that moment, the man lifted up the sewer that he went underneath while the 2 girls were having a conversation and was surprised to see how heavy it was now.

 "Did you know that you can be reported to the police for this kind of conduct?" asked the blond boy sitting on the lid.

 "Nin-nin!" the man said in a low voice and disappeared down the sewer again.

 ~~~~Time skip~~~~

 It is now period and it's English Self-study, but of course, who needs English self-study when the British blood is flowing through half of your body right? Mia being Mia, she believed that after 15 years of British Education, she can do the English test with her eyes closed. So in lessons like these, the girl use it to catch up on sleep or read her favorite book on her lap with the textbook open on the table for fearing the teacher would find out. But oddly enough, she wasn't in her seat today.

 "Hey, where's Mia?" Misaki asked, looking around the class.

 Somewhere else, the blond 'ninja' was looking around as he entered the bathroom. Opening the door of one of the cabins, he found a familiar girl sitting on top of the tank, reading 'A Study in Scarlet' (what did I tell ya?).

 "Suspect found." she shut the book with a smirk but right before she could stand up, the suspect has already bolt out the door. Mia tried to run after him but lost him at the basketball court.

 Afterward, she met up with Usui and told him about what happened.

 "So you found him ... In the boys' bathroom?" Usui asked with a truly 'What the hell were you thinking?' face.

 "Yeah, but he got away, either I'm too slow or he's inhumanly fast." she replied, disappointed.

 "Mia, didn't you promise me you wouldn't do anything reckless?"

 "Yes, that's why I didn't climb up to the court light to chase after him."

 "And you don't see any problems with going into the boys' bathroom?" the boy face-palmed and massage his forehead slightly.

 "Nobody saw me anyway."

 "Could you at least be more careful?"

 "What? You're afraid I'd get raped in the boys' bathroom?"

 "Mia has no sense of self-preservation. Are you trying to make me angry?"

 "That's the problem with you. You're too cautious to move a single inch. If we don't take actions, we'll never able to catch that guy." the casual conversation has now turned into a heated argument (first couple fight).