In the end of Denkigai no Honya-san there is a short scene with a bunch of Uma's employees and the main guy doing the morning drill with them, repeating the standard shopkeeper phrases such as "Welcome, dear customer", "Thank you for your purchase", etc.
From the short frames near the advertisement cut, it can be seen that the Uma store is several stories high and pretty big on the outside. But we only see the inside of the section where the main characters work. That last scene shows that there are a lot more employees in the store and that they work in sections divided by other topics. It seems like there are sections dedicated to items intended for adults.
What is the topic of the section we see? What are the topics of other sections? Also is there a name for such big manga stores?