The first two links for Rihona and Airi were the same.
You mistakenly pasted it twice!
OK, for these singers. I have to say Rihona sounded like the usual JPop ballad voice type, not very strong at belting and more of that nasal. resonance.
Airi seems like a stronger singer to me. She can sing high and belt! She has over 400k subs on YouTube, so she's probably making some good money and is popular too.
This was a good and not-easy song to cover, with LiSA's constant high belting.
This collab song seems like a better representation for her in terms of versatility. Some of talk about this bringing her out of her usual idol fare:
https://www.youtube.com/watch?v=BnTJ_BEM_9U.
This is from a live performance
https://www.youtube.com/watch?v=d8-2p0D2Hfk and she sounds even stronger.
This is a song called, "I Became Someone Else's Girlfriend"; a live performance -
https://youtu.be/pCTQkFpznKU?si=Zj4pos8bYm7NgUDF - and I like her acting/vulnerable singing, which is fitting for the song and character-singing.
She seems like a part-idol, part-anisong singer.
I dont know any filipina who works in japan apart from Beverly
https://www.youtube.com/watch?v=y10_zkbRnAs
Beverly is a strong vocalist, definitely with Philippines good-singing gene. Is she the one who did a live collab with Keiko once upon a time?
In fact, in this song you shared the link she sounds comparable to R!n/Gemie who works with Sawano Hiroyuki and is known for a couple of favourite Attack on Titan songs, though I think Beverly is stronger at high mix belts (a higher ring).
I think she would be a solid vocalist to have singing a Kajiura song or two, in the vein of JUNNA (a young, energetic, belting female singer).
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