Mafumafu hits an F6 in nibyoukan. Touyu also hits a really high note at the end of deaf room. Glutamine hitting F6 is questionable. There's a high note in rimokon but i think it's just pitch shifting, not actual squeaking.
Errr, i meant Gikyoku to deforume toshi. Touyu hits an E6 in that. I listened to the NND magicians operation and didnt hear anything higher than G#4, so I'm wondering if you are talking about the album version? Also I'm wondering if that yuurei yashiki no kubitsuri shoujo high note is real. Some pitch shifting can sound very realistic. Take kumakuma~ 's tokyo teddy bear, where they sing a C6 but it gets shifted up to a C7.
So... i mean... in terms of glutamine, the highest i've heard was the B5 in rolling girl.
touyu seems like he really hits the E6 in gikyoku to deforume toshi
mafumafu sounds like he really hits the F6 in nibyoukan.
So... that C7 is going to be questionable, since it can be pitch shifted, but mafumafu may be able to do it. same with this touyu B6 even though I haven't heard it.