The letter Shouko tore up was her love letter to Hayami
A: "The first time I saw you" / "I like you"
B: "I want to tell you" / "these feelings" / "now"
C: "so..." / "after school" / "gymnasium"
D: "Tamemizu Shouko"
This makes me wonder if Shouko actually sees Hayami as a guy or if she is just gay