...Wakaki, you are too good with this... Foreshadowing everything from the start of the series.
Emblem = Drawn detailed in the first chapter.
Demeter = Name of the place which sells omu-soba bread.
Hakua = "This place is used to be ancient battle field"
Theater = Only place that was not rebuilt.
This chapter is all about solving problem that people might have been thought as a plot hole - Why weiss capturing squad is all around Maijima city? Why all goddess are in a single place?, this sort of things. Very clever, Wakaki.
Now, here are some parts that could be interesting plot device for establishing the setting of Maijima city;
1. "Akanemaru" - That ship where Keima + Chihiro had the ending. It's really strange how that ship is just... there. It's just weird; must have reason for it.
2. Hakua - There is high possibility that Keima will meet Hakua from the cave when Keima saw group of weiss.
3. Nikaido and Rimyuel - I think they will start to act one step forward of Keima's group.