Mei's father, Aihara Shou suddenly returns home. While Yuzu is surprised to meet him for the first time, she explains to Shou how hard Mei's been working for the academy. However, Mei screams at her to stop  when Shou just silently averts his eyes with hesitation. Shou tells his daughter, "I'm not returning to the academy." Yuzu is unable to say anything as Mei runs away to their bedroom, and that night she tries speaking to Mei again.
Uh, when there are two vectors that aren't 
zero vectors, as shown in this diagram here,
Wenn wir zwei Vektoren haben, die nicht
gleich null sind, wie in diesem Diagramm gezeigt,
Hm, quando há dois vetores que
não são nulos, como no esquema,
Э, когда существуют два
ненулевых вектора, как на рисунке,