Definitely. Super pleasing to listen to. It doesn't sound sped up or anything. Probably just some tuning. It's so fast and all the transitions to falsetto whatnot are super buttery smooth. It's super impressive to be able to control your voice that well. And you gotta be lucky to even have a really good voice. Everything lined up perfectly to create an amazing singer.
I just finished Lastame, absolutely love the opening and ending, been listening to them a lot recently! The story got me so hooked I finished the anime in 2 days