Thank you for picking that out! Kana is meant to have a club, Aiko a heart, Yumi a spade and Haruka a diamond. The meanings of these are somewhat linked to this information, but I just thought it'd add an interesting touch for all of them to have a unique symbol associated to them.
As for those errors, whoops, I'll make sure to fix that in future updates. I probably won't be doing an update again until the majority of the story is in, as I don't want to keep making people replay the intro sequence. @_@