Turns out the one spreading the rumors was Hashimoto, who did so at the behest of Sakayanagi. Shortly thereafter, Sakayanagi appears before Class C and she informs them she has evidence regarding the rumors about Ichinose.
Hey... could I ask you a strange question?
أخبرني... أيمكنني طرح سؤالٍ غريب عليك؟
¿Puedo preguntarte algo?
¿Puedo preguntarte algo?
Ei... Posso fazer uma pergunta estranha?
Можно… глупость спросить?