Mama-san’s volleyball club refers to the volleyball club Asahi said she went to in chapter 1, she’s probably started dragging Souta along with her after the hospital scene. No chapter was skipped :p
From what I can see the only instance of Azuru using any kind of gendered term for Renri after that page is on page 12 where he refers to him as 彼 which means he/him
Funny, but a bit homophobic. Disappointing. Guess what, author, lesbians will still only be attracted to girls even if you make them spend time with only guys, but I guess you’re not ready for that conversation.