Oboetete ii yo/DuDiDuWa*lalala

"Oboetete ii yo/DuDiDuWa*lalala" (覚えてていいよ/DuDiDuWa*lalala) is the first single released by Kotoko produced by I've Sound and under the Geneon Entertainment label. "DuDiDuWa*lalala" was used as the ending theme for the anime Tweeny Witches. The single reached number fifteen on the Oricon weekly charts and charted for seven weeks.

Track listing

 * 1) 覚えてていいよ / Oboetete Ii yo—4:11
 * Composition: Tomoyuki Nakazawa
 * Arrangement: Tomoyuki Nakazawa
 * Lyrics: Kotoko
 * 1) DuDiDuWa*lalala—5:17
 * Composition: Atsuhiko Nakatsubo, Kotoko, Johann Strauss II
 * Arrangement: Atsuhiko Nakatsubo
 * Lyrics: Kotoko
 * 1) 覚えてていいよ / Oboetete Ii yo (Karaoke) -- 4:10
 * 2) DuDiDuWa*lalala (Karaoke) - 5:17