The end seemed rush. Basically The demons in this story are people who got isekaid from japan because there seems to be a connection, so male mc is also a demon. They have unique abilities which for Sena, is basically make things out of wishes(???). The bard (Also a demon) in the castle which is like the foster father of Spica can brainwash poeple by his songs. He used it in the past to make them believe that spica is a daughter of the king, which didn't work with Stella but she still wants to adopt them though lol. Funnily, most people in the castle realized that spica isn't a legitimate daughter but still didn't matter much since Stella is just messing around.
The bard just challenge them to stop because its meaningless and wants a happy life for Spica. Also, he revealed the secrets of demons to them as well as the possibility of returning to japan. It seems that staying too long in isekai will soon erase their memories. The secret to transfer to another world is in the sphere that Stella broke at the first chapters.
Anyways, Spica followed the bard and realized what Stella was doing and got mad. They started fighting with stella winning due to the inability of Spica to change what is crafted/made by Sena (Which are all big earth statues of Stella), the earth statues surprised spica then got spooked as well as slapped by the real stella. From her dreams after getting slapped, it was revealed that Spica's past got revealed and I dont understand what occured, dunno if bard is the real father but then left them or something but one thing is for sure is that Sena is her actual brother. After that they talked it out with Stella not wanting to return and let Spica rule then advised her to make a country fun and good country for her, not for stella or something, while she will make a country that will destroy it.
The end is Spica returned everyone into normal and promised to do better in ruling. Stella realized that Sena is from another world and wanted to build a kingdom there as well from which he finds it interesting, so agreed to helping her. The bard stated that the orb stella destroyed can be fixed in the cave or he inherited something similar, I dunno but now they have a way to get into another world. So fast forward to months, Sena and Stella is in japan taking a break, talking about a story they published about what happened and then Sena tells stella that her presence (?) got much better, or she fits better now or looks better now, I dunno then they stella suddenly said that the break is over then pull sena so that they can move one and continue their market research. After that It goes back to the other world, with Monica being like a receptionist there. The atmosphere on the stella kingdom looked more like Wendy's then there's this sign written as "New Work". The last scene is I think Sena and Stella coming back with Monica wanting to take her with them to Japan next time. That is all, sorry for my bad writing.