What are your specs?

Just in case, right-click on the game in your library -> Properties -> Local Files -> Verify integrity of game files.

Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz (4 CPUs), ~2.7GHz
NVIDIA GeForce GTX 1060 6GB
DirectX Version: DirectX 12
8192MB RAM

I have tried to verify integrity of games files twice, but it doesn't worked. It is still been stuck on the "now loading" screen.

Are you on Windows 10 or 7?

There were reports of this infinite loading screen bug on Windows 7 (this OS is not officially supported by the DX versions).
https://gtm.steamproxy.vip/app/1502990/discussions/0/3129415222168618858/

The user in that thread recommends to "force it to shut down and start again".

Mine is Windows 10

PS. I have played Atelier Sophie for 2 months after buying and it works fine and now I'm downloading Lydie&Suelle to see if it works.

Sophie is running on a much older engine, while Firis and L&S are very modern games made on the same engine as Ryza.

Maybe it's your RAM. I just checked RAM usage, and Firis uses about 3GB of RAM. Try quitting your browser and closing all other background apps before launching the game.

I have tried Lydie&Suelle and it is fine. The problem is seen only with Firis.

Now, it works, i have uninstalled and reinstalled the game thrice and then the problem have been resolved.