Ayumi finds the note inside the classroom 5-A. It says "Whenever I think of you my heart beats twice as fast. Whenever I see you I feel like I’m looking at an angel. If you love me as much as I love you, bring this letter to our next meeting. Your Secret Admirer. Hataru Kanzaki.". It is one of the three items that the evil spirit wants from Ayumi.
Significant plot details end here.
The letter's author is a reference to one of the collectable nametags from BloodCovered/Repeated Fear: Hotaru Kanzaki. The typo in his name is still present in the game.