Re: ティアルーシと地下迷宮 (RJ186272)
I'm about a day late, but it looks like the new demo released (I think - I don't quite understand the appended blog post, but the demo I'm playing is different than the original version, whatever the case); I haven't played too far, but it appears that you can now go to the area to the top right of the heroine's house after defeating the first boss (or so I assume - I didn't try until afterwards), which will take you to town. It looks like there's a couple of recollection scenes with the blue-haired party member that you can watch by interacting with the desk in the heroine's bedroom, too. There may be more, but I don't have the time to play further right now.
Edit: I had the chance to play a little further and it looks like you eventually meet up with the blue-haired party member and can enter a dungeon, albeit only the first level. The only enemies in it are the slime and boss creature that were in the first dungeon, but at least this time you can also see their animations with the new party member.