I've been keeping track of the 9ki blog and recently Eripon has been talking a lot about going to karaoke alone.
Just today, she posted a list of the songs she most recently sang.
It was almost 30 songs long, or approximately 2 1/2-3 hours long by my reckoning.
The way it sounds, it's not that she's going alone because she has no one to go with.
It's almost as if she's going alone intentionally whenever she has some free time.
The only other member I've heard of that likes to go to karaoke by herself all the time is Reina.
Maybe Eripon heard that her fellow Fukuoka native, who happens to be a top 3 singer in H!P, does it frequently and wanted to emulate her.
Whatever it is, I think she has a reason for it, and that reason may be to get more practice singing.
I may be jumping the gun a little here, but if she is, that's a very good thing.