The Song

Watashi-tachi ni Naritakute (私たちになりたくて ; "Wanting to Be Together with You") was the fifth ending theme song for the anime, and was used in episodes 128-140 of the fourth season. It also played in the background during the scenes with Chibiusa and Pegasus in episodes 158 and 159. A new version of the song was also used as the ending theme for the first part of Sailor Moon Eternal.

The lyrics were written by Yasushi Akimoto, the music was composed by Nozomi Inoue, and the song was performed by Miwako Fujitani. The version used in Sailor Moon Eternal was performed by Yoko Ishida.

Elena from Pretty Cast performed a cover of the song on the Best Song Collection CD.

Info taken from: Wikimoon

Japanese Lyrics

あなたと出逢ってから
胸の奥で光ってる
愛しさが切なくて
静かに瞳を閉じた

なんでもないしぐさも
ごく普通の言葉も
思い出すその度
涙が出そうになる

恋はＬｏｎｅｌｙＬｏｎｅｌｙｈｅａｒｔ
ひとりぼっちよ
ＬｏｎｅｌｙＬｏｎｅｌｙｈｅａｒｔ
喜びも悲しみもいつだって
私だけの夢の中
恋はＬｏｎｅｌｙＬｏｎｅｌｙｈｅａｒｔ
だけどきっといつの日にか
あなたの強い腕に抱かれながら
私たちになりたくて・・・・

あなたのすぐ近くで
ずっと私まってるの
気づいてはくれなくて
なんどもがっかりしたわ

誰かを好きになると
何故こんなに苦しいの
私だけひとりが
風邪をひいたみたいに・・・・

今はＢａｂｙＢａｂｙｌｏｖｅ
どうぞお願い
ＢａｂｙＢａｂｙｌｏｖｅ
淋しさに負けそうなその時は
手鏡を覗かせて
今はＢａｂｙＢａｂｙｌｏｖｅ
泣いた夜もいつの日にか
昔をなつかしんで笑い合える
私たちになりたくて・・・・

誰も知らない
Ｓｅｃｒｅｔｔｅａｒｓ
拭える一は
Ｏｎｌｙ
私より
私たちになりたくて・・・・

Watch the original ending theme song here. In order to listen to the version used in Sailor Moon Eternal, click here.

Furthermore, I absolutely recommend to check out Rin's own, very detailed translation and Myrna's incredible in-depth analysis of the song and corresponding animation sequence!