I meant Reira, sorry. I was surprised because Leila is a real name, Reira isn’t.
The fanwiki confuses me further:
Layla Serizawa (芹澤レイラ), better known as Reira (レイラ), is the half-American, half-Japanese lead singer of Trapnest.
Although her name is often transliterated as “Reira”, her actual name is “Layla”, after Eric Clapton’s famous song of the same name.
I’m not going to read more to avoid spoilers, maybe it’ll be addressed later.