Friendships With the Other Members
Since the girls of Morning Musume and Hello! Project are around eachother so much, it's obvious that Yoshizawa would naturally become friends.
Gotou Maki
Gotou was probably Yoshizawa's first friend in Momusu, because they were the same age and enjoyed some of the same things. (Styles of clothes, shopping) An interesting tidbit is that Gotou was actually the member in Momusu Yoshizawa admired most, so including getting to be in Momusu, Yossi got to meet and become friends with her idol.
Ogawa Makoto
Seemingly new, Ogawa and Yoshizawa get along very well. At the end of the year Haro Moni (Hello Morning) show, Ogawa accused Yoshizawa of skipping out on going shopping for friendship braclets with her. (Which they actually did buy some...just odd braclets.) So it's almost an ongoing joke that Ogawa and Yoshizawa are a couple, also maybe from "Mr. Moonlight~Ai no Big Band", where Ogawa was the girl Boy-Yoshizawa went after.
Yaguchi Mari
Yaguchi was the person who came up with the nickname "Yossi" for Yoshizawa. (At least this is what the official Momusu manga says) Yoshizawa jokes around saying that if she were a guy, Yaguchi would be her perfect girl.
Ishikawa Rika
There isn't truly much about these two, other than being normal friends, than the fact that since they were both fourth gen, Tsuji and Kago stuck together, so it was Ishikawa and Yoshizawa who stuck together. Also, it was commented that Ishikawa and Yoshizawa would fit, because one is so girly and the other tomboyish, but in truth, Yossi doesn't like totally girly girls!
Fujimoto Miki
The only reason I'm listing Fujimoto is because of their voices mostly. Since both have quite low voices, they are paired in duets a lot. But they seem to be friends also, an example being in the making of "Go Girl! Koi no Victory!" they both were singing and dancing some of the parts of the song together.
Yoshizawa is probably friends with all of them, she jokes around a lot with every member, but these seems to be the ones that stick out.