I Don't Understand37,240 Views SingerKagamine LenVocaloidProducerKurokawa MasakichiProducerViews BreakdownNiconico30K ViewsYouTube7.1K ViewsDaily Views511/16111/17211/18211/19511/20111/21411/22VideorefreshRefresh Song DataListenYouTubeNiconicoVocaDB