I'm not going to say she has no personality but she's a boring character to me. As are all of the Lucky 星, つ星 characters--hence why I couldn't get into it.
I'm gonna branch out and go with Natsumi Mizuki from GetBackers. The 表示する isn't outstanding and definitely has its pitfalls, but she was possibly the worst character in the show. Even the blind girl with a solid 20 lines has もっと見る of a personality than her. The sub-characters were pretty awesome in GetBackers, and while I wasn't expecting another Kazuki または Paul, Natsumi was just an average, cliche, no-point-in-being-there high school アニメ girl.