Why couldn't Kamiyama just tell Okamoto that the letter was from another girl at the very start? Heck, why didn't she just give the letter to Nakai herself? The letter wasn't from her and she could've have clarified that information to the guy without having to reveal the name of his admirer to any unnecessary third party. If Kamiyama just felt awkward about giving a love letter to a guy, regardless of whether or not the letter was from her, then she could've just told Okamoto who the letter was from and make him swear to not reveal that information to anyone else. The main conflict of this oneshot has to rely on an unrealistic lack of communication to stretch out the drama before the inevitable conclusion.