When asked about "I'm so happy (L'Acoustic version)," yukihiro described it as "lounge music." He says, "I guess if the person who wrote the music calls it 'lounge,' then it's lounge music. (laughs) It's just the way it feels to you. Even if it's house or hip hop or bossa nova, just say 'it's lounge' and there you have it. Lounge music to me is something you can relax to. You might be able to dance to it, but it's more cooled down than club music."
