I've seen the raws (ch.11). Please explain Kusakabe's hair, like... how??!

this tumblr account is translating the chapters https://honyakusuru.tumblr.com/post/612328525084622848/blanc-chapter-9-english-translation go to chapter 8 so you can fully understand the hair situation ╥﹏╥

Ah thank you but I've already read that. I'm at chap11 now, kusakabe's hair grew really fast, that's what i mean by how