I found a similar one; the front and back hair are the same as this hairstyle, but the hair near the ears is styled differently. It seems to be based on this one.
https://booth.pm/ja/items/4491108
found by @shiro -> https://forum.ripper.store/post/17924

@BLACK0NYX said in LF: DEVIL's MANIA! for grus:

For Grus

Thank you so much! 😳