Author: "How do I get these girls to be closer?"
Author: "Oh I know I'll introduce some pick up artists who try and coerce one of the females leads to come with them and have sex."
Hopefully next chapter is Sei and Yoru having a proper conversation to help Sei move on but usually with these things it'll most likely end up just causing more drama.
A lot of manga involving predominantly female casts usually hit you with yuri subext throughout the manga, while this one started with straight up yuri but has almost completely regressed since then to subtext at most.