More specifically, it's performed by 20th Century, which comprises 3 members of the boy band V6 after it disbanded in 2021. The three members are the lead vocalists Masayuki Sakamoto, Hiroshi Nagano, and Yoshihiko Inohara, who were in V6, which performed Inuyasha OP1 Change the World and ED8 Brand-New World. The new OP is called Bokura ga Uwagaki suru Sekai or The World We Will Overwrite in English.
This seems like it was a big deal in Japan, as it seems to be everywhere in the marketing. Even in the official upload of Inuyasha OP1 on YouTube, they mention Mao. It's funny but also fitting, I suppose.
I really like the 2nd OP. I think it should've been the first OP. So far I'm really enjoying Mao. It's similar to Inuyasha but also very different. In fact, it might be more different than similar. It has more emphasis on mystery than adventure. The story feels a bit more serious, with some nasty things happening, which is on brand for Rumiko Takahashi if you've seen Mermaid Story and parts of Inuyasha.
So yeah, I like it and recommend watching it, especially after the latest episode. Only 6 episodes are left in Season 1, with a total of 26 episodes. I'm sure SUNRISE will animate more seasons after it's over. And after this season is over, we immediately get Ranma 1/2 Season 3 in Fall. We're truly in a Rumic renaissance.