books 1-7: Tramps Like Us, Volumes 8-14 by Yayoi Ogawa
I find this manga series bittersweet. Sumire and Hasumi break each other's hearts, and I don't deal with pain like that well. Mostly everyone ends up in a happy situation, which is not always guaranteed in Japanese comics, so I got through it okay. I had to read in a marathon to get past the pain and to the happy stuff, though, to ease my mind.