I suppose it's a "glass is half-full/half-empty" sort of deal, but I've always known Ayu to have a lot of songs that can be read as pessimistic. Very many of them are dark, desperate, lonely, or apprehensive; and the happier lyrics usually have some tinge of bittersweetness or doubt.

Moments is a song filled with beautiful imagery as a reassurance of her dedication to someone. But she says that she is dedicated so much to this person, that she would even make herself disappear and be alone, if it meant that the person would be happy.

A Song for xx is very, very pessimistic. She talks about how she is lost and confused and scared and, the entire time, very much alone. She says how she even got so used to feeling this way, that she assumed it was just normal to be so sad and alone.

Far away is quite pessimistic, as well. The final chorus sums up the entire song by saying that onlookers thought the couple's love was going to be everlasting, but in fact, it had a definite end. The final line is: "Summer is coming soon, one without you," which doesn't seem to hold much promise.

appears is the story of how a couple seems happy, but the two of them know that that is not the case.

I am... is a song of pleading with someone to give her something she knows she won't get. She says that, even if it is all a lie, she doesn't mind being lied to if she never has to live outside the lie.

In M, she says that everybody is in pain, and she even prays to Mary that she never falls in love again, so she doesn't have to feel the pain she is now feeling.

In Because of You, she blames her problems on the fact that she is in a hopeless love with someone she wishes she never met.

GAME talks about how she is so hung up on someone who she has parted from, and she can't stop things from going wrong.

HAPPY ENDING and HOPE or PAIN are very pessimistic, too; the first talks about how she doesn't deserve to talk about the meaning of happiness, and the latter is about how she expects rejection by a lover.

End of the World is says that sometimes you just can't help but notice how pitiful you are, and you crash into a wall. The whole song is mostly quite pessimistic, even the seemingly positive theme that someone finally made an attempt to understand Ayu (when she puts a lot of stress on how there has only been one such person in her life, and he/she wasn't necessarily successful).

is this LOVE? brings about rejection by a lover, and she makes the realization that this [painful betrayal] is what love must really be.

Several seemingly upbeat songs, including too late, bring down the mood by talking about how she is hurrying through life and missing out on enjoying it.

still alone talks about how she had finally found love, and then the lover left her to follow a dream, and she was still, after all, as alone as she always expected herself to be. She is left alone holding on to a promise that no longer matters.

vogue makes commentary on how one day something is loved and adored and revered, and the next it must just silently wilt and blow away like a dead flower.

Endless sorrow is a another song of love and dedication, but it is filled with lines that say how hard things are and will continue to be.