Recommend me JPop songs about "Love Letter"

[terra]

Ok, I was making another CD compilation about love songs...then I had the idea of gathering all songs about or titled love letter together (obviously songs entitled love letter would talk about love love letter/love isn't it) lol

So I've collected some but I feel that I have such small amount of "Love Letter" songs...there are

Love Letter - Gackt
LOVE LETTER - BoA
Kokoro no Tegami - BoA
LOVE LETTER - Ai Otsuka
Koibumi - ELT
LOVE MAIL - Ami Suzuki
Key ~eternal tie ver.~ - Ayumi Hamasaki
Jojoushi - L'Arc~en~Ciel

I guess that's all that I have

So could you guys help me by listing some songs like ones above?

Thanks, I really appreciate it!