Kusakabe Yuki overhears some girls saying mean things about her. Gossip is not an uncommon problem among high school girls, but Yuki is particularly worried that it's happening because she's a demi. Tetsuo is sympathetic to thr concern and makes up his mind that, as her teacher, he must protect her. Hikari, a fellow demi, feels the same way.
I think that's the reason.
.أظنّ أنّ ذلك هو السّبب
Ich denke, das ist der Grund.
Creo que es la razón.
Creo que es la razón.
Selon moi, ceci explique cela.
Credo sia questo il motivo.
Creio que a razão seja essa.
Наверное, это и есть причина.