Thanks for the chapter :D
Izumi's flashback this chapter hints at some sort of family trauma, presumably stemming from him being disowned by his family. He wants to know people before dating them, as shown in a previous chapter. I suspect this is because he sees other people spending time with him as "burdening" them, and that he actually has very low self-esteem. I wonder if he acts all flashy and helpful to everyone as a way to feel useful.
Anyways, if this is the case, the winner of the free-for-all will be determined by who can convince Izumi that he is worth caring for – until that happens, he won't budge at all. In this respect, all four girls are actually still in the running. Nanao is too superficial, showering him with affection that comes out of nowhere, which ironically makes Izumi less convinced that any of it means anything. Amane has nothing going on whatsoever. Hakua really cares for Izumi, but the extent to which she knows Izumi is yet to be seen. Haru might be the most behind, as her tsun-ness would actually make Izumi feel awful.
Conclusion: Hakua is still best girl for now.