"When I was crying over us getting a 'fake gold' in middle school, you sat there stoically on your smug ass like it didn't even matter! When I said I 'love you,' I left out 'being rattled'. I think I'll go give myself to Sensei ... if you don't mind.Who's crying now, Kumiko? Who's crying now???"
Yeah Sachi may have a thing for Minami but she wouldn't trust her not to tease her or worse if she confessed. I forget which chapter had it, but Minami basically admitted she and her crew (Sachi etc.) were "safeties" for each other so they wouldn't be loners even if they screwed up socially.
"Anata no nekutai wa bachigaidesu. Watashitachi ha watashitachi no gaikan ni chūi suru hitsuyō ga arimasu. Ki wo tsukete! Tomoko-Sama ga Miteru!" This made me laugh. I can see tomoko reciting sachico's lines.