I doubt it's Tyrano Builder.
Even though I have never heard of this engine before from what I read right now on Google it seems like this is a Japanese engine that was created back in the day and didn't have English support
So unless the dev is Japanese which I somehow doubt I don't think they are using Tyrano Builder.
If this isn't a GameMaker engine, my second guess would be the Monogatari Visual Novel engine.
This engine is also Japanese sure but it has official English support and I've seen many people in the West use it to make visual novels.
Of course I could be wrong but after watching this overview I'm 80 percent sure its the monogatari engine or a variant of it
or it could be godot: