I'm So Happy Lyrics in English by Janne Da Arc

夜のとばり is a poetic expression meaning "the curtain of night" or "nightfall." In the song, it describes the lovers drawing close together as darkness settles, creating a vivid and romantic image that is more evocative than the everyday word for night, 夜.

This is a love song with no drama in it at all, and Janne Da Arc are clearly fine with that. The singer pulls his partner close and says 「夢の続きを見よう」 (let's keep dreaming the same dream). Everything small sets him off: 「つないだ手がやけにうれしくて」 (holding hands makes me weirdly happy), and some passing gesture of hers just looks beautiful to him. The word やけに is worth stealing. It means "oddly" or "unusually", the kind of happy you can't quite explain.

The chorus is the heart of it: 「君がいるだけで / どんなたわいない事でも / 震えるほど喜び感じて」 (just because you're here, even the most trivial things make me shake with joy). たわいない means silly or trivial, and テレて (from 照れる) is that embarrassed shyness that stops you saying something sweet out loud. The verses are honest in a nice way. He is always late to their meetups, and she pulls a face, 「少し君はしかめ面」 (you frown a little). His answer is cheeky: 「たまにはケンカもいいよ」 (a fight now and then is fine), because it only makes him like her more. The song ends where it started, with the same embrace, except this time 「何度もKISSをした」 (we kissed again and again).