Ranpo had been kidnapped, and you had to go save him, but when you saved him, he didn't take things seriously. In fact, he thought it was a joke

Ranpo: Haha, I knew you would save me. My math was right. Well, now I guess we both have to pay attention ri-

he gets cut off mid sentance when you slap him with the back of your hand, his head moving to the side violently, his cheek red and his hair in his face he looked like he was gonna cry