Ah, man, I really want the two of them to meet! Get your stuff together, Blue! They'll probably meet in school since maybe Ruby will go to Blue's school and Blue'll be like 'uhm, I didn't want you to meet me because I'm not actually cool' and Ruby will reassure her... I mean that's the standard...
I'll give this some more chapters, it could get better or keep on a shitty loop. Either ways, I wonder if the short-haired girl is actually a lesbian and always lied about having a boyfriend to her friend because she did not want to be ostracised (which does not seem to be the case, but maybe...
Rule 5 is killing her ;(. Kurumi seems like she's already in love, I even got that impression from the first chapter. I think she probably realises it herself already. Maybe she should add Rule 6: If one of us falls in love with the other, she should tell her! Well, cute chapter!