Yaku is respected for his abilities as a strong libero. Karasuno's Yū Nishinoya had confronted him about his talent as a libero from his experience of playing against him in the same position. Off the court, he is supportive of his team and often takes on a mother-like role when speaking toward, or of them, similar to Sugawara. Because of this, Yaku and Sugawara get along well. Yaku is also insecure about his height, and his teammates have once stated that it's a taboo subject after Lev pointed it out (he was subsequently kicked by Yaku).
(Source: Haikyuu!! Wiki)
