Before anyone starts, yes Yamada more than likely voted for Ichikawa instead of Kanzaki to join the group. However that mostly due to Yamada wanting to help Kanzaki go with Hara's group, which is why she signaled Ichikawa for assistance (because Ichikawa is the only other one Yamada knew who was aware of Kanzaki and Hara's situation). Also the other two guys aren't people Yamada views in high regards. So Yamada voting for Ichikawa can be interpreted as her choosing the best option for Kanzaki and Hara's relationship as well as getting the only guy she tolerates in the group. It doesn't necessarily indicate that Yamada is interested in Ichikawa, romantically.
Also, I know I said in a past comment that Ichikawa wasn't "Mr. Popular", but geeze! Even Yamada's friends don't seem to like him that much. I expected at least the tall ponytail girl would tolerate Ichikawa since he got out of the way so that her friend and Yamada could make up (which helped patch things up between the ponytail girl and her friend) but nope, she hates Ichikawa as well. It does make the idea of Yamada and Ichikawa becoming a couple (whenever the author can get around to having Yamada interested in Ichikawa) more interesting if Yamada's best friends wouldn't approve of it.