^ these feelings men 
About the groups, I will leave this:
KÜHN and the single debut 
And a live show from 2014 by me-me* (I like all the songs, but Mirror kills me...and the choreo) 
Maybe the groups are disbanded now, but they put a great energy on her dances and songs 
In some kind of way, they are the "sister groups" of EbiMasu 
After or During EbiMasu, these groups were formed.
me-me*, KUHN, marshmallow 3d+, Million Girls Z, P-Cherry (the duo of Rin Sakuragi and Sakura Yura), PINKEY...
EbiMasu really paved the way to AV Actresses to step outside of the AV Box, and do the things they love, like singing.
And it all started when Mihiro, Rio, Yuma, Acky, and Sola wanted to prove that they can sing.
