>>3143961You're mostly right, they both obviously love each other a lot considering how much they're willing to sacrifice for each other but it's not really romantic or sexual. I think it's worth mentioning though that Kirino is at least canonically bisexual considering she plays eroge aimed at males and clearly gets excited by the ero scenes.
Ruri's "if senpai asks me to I'll do it" line is quite specific in context though, don't forget that immediately after she explodes in indignation when he suggests that he helps her, so don't assume that means she'd do anything for him.
