The link between all the members seems to be that they were members of the Japan BGM Philharmonic Orchestra (now
JAGMO). I couldn't confirm the real names of 3 of the members. However, I can make some accurate guesses.
There's an archived JBPO member list
here. These are the only performers who are Facebook friends with all other Takuan members:
Marina Bano/場野まりな (violin) - [
Facebook] [
JBPO]
=
mufflche
Edit - confirmed
Yuka Sagara/相良有香 (viola) [
Facebook] [
JBPO]
=
jyson
Edit - confirmed:
https://twitter.com/l0w0l_sa/status/1212649858521190400
Shin-ichi Hashmoto/橋本慎一 (contrabass) [
Facebook] [
JBPO]
=
???
Edit - confirmed:
https://www.facebook.com/shinichi.ha...57222311021648