Well, there are too many songs that make me remember my loved ones... but here are the most important, I think:
5th: You're the One [Amuro Namie] An encouraging song for sad days.
4th: Lucy [Sakamoto Maaya] Although it's an instrumental song, it's so sweet and a bit nostalgic...
3rd: BIKE [Sakamoto Maaya] Oh... I didn't notice how far is childhood...
2nd: First Love [Utada Hikaru] This song express a lot of nostalgic thoughts, so I can't stay serious...
1st: I WILL [Amuro Namie] Definitely, the song that makes me cry every time I listen to. It's really difficult to forgive my boyfriend with this song... and some sad moments... Straight to the heart!