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.
Vice President Kiriyama, I want you to post 
this information on the message boards.
نائب الرئيس كيرياما، أريد منك نشر 
هذه المعلومة على لوحة الرسائل
Ich möchte, dass du
das ins Forum postest.
Vice-président,
Vice-presidente Kiriyama,
Vice-Presidente Kiriyama, quero que coloque
essa informação no quadro de mensagens.
Зампред Кирияма, выложи это всё
на доске объявлений.