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.
It's impressive to put your old 
demons to rest with your own power.
من المُذهل تجاوزكِ لظلام الماضي بقوّتك
Nur man selbst kann sich von den
Fesseln seiner Vergangenheit befreien.
Solo uno mismo puede triunfar
contra su pasado.
Solo uno mismo puede triunfar
contra su pasado.
Seul l’intéressé
peut surmonter son passé.
Possiamo contare solo su noi stessi
per lasciarci alle spalle il passato.
É impressionante ter forças para
lidar com seus próprios demônios.
Смогла сама со своим
 прошлым разобраться.