I already have High-Energy (Momo-i Version), but what the hey, right? I like both versions. As for the second song, Momoi's part is all rap. It's actually pretty good, but I'm not really into that type of music, but Sakunyan's part is not rap, so I like it just fine.
Sound quality, at least for the first song, is very similar to the Momoi only version in her album, "Sunday Early Morning." Second song is slightly worse, but in today's standards, both are okay, I guess.
I suppose I should have listed "Lumica" single under "Kawaii! JeNny," too, but that one was all Momoi, so I ended up listing it under her name. Oh well. It's not like my site is 100% consistent anyway.
