Talk about another blast from my teenage past! I loved Zodiac P.I. when I was in high school, as it combined detective stories with Western astrology, two things I've always loved. I will note that I find it interesting (now that I'm an adult, as I didn't consider it much when I was 15,) that Natsumi Ando wrote a series centered around Western astrology, where most manga would focus on the Chinese zodiac. Either way it's a fun read and there are lots of little blurbs and side notes concerning the zodiac signs found in the different mysteries solved by our plucky protagonist, Lili, who moonlights as Spica, the Zodiac P.I.
Most of these stories are like fluffier, less morbid cases of mystery told in a similar vein to cases from Detective Conan. Of course, Spica solves cases by interacting with the various spirits of the twelve Zodiac signs that live in her magic ring, as they read the various horoscopes for different people involved in the cases she solves. (Naturally there's a love interest in the form of the token Childhood Guy Friend who's a tsundere with an apparent allergy to females. You didn't think you'd completely escape those tropes, did you?)
I think my issues with this manga mainly boil down to two things.
The first is mainly just a quibble I have with the creator's art style. Compared to her series Kitchen Princess, both Lili and Hiro (the Childhood Guy Friend) in this series look almost like copy-pastes visually of two characters from Kitchen Princess. Really, it's a stupid nitpick at same face syndrome, which is pretty common in anime and manga; the way the characters are written is what sets them apart.
My second issue is with the translation. I hadn't noticed it much as a teen, but after learning how lazy Tokyopop tended to be with translation as an adult, I've noticed a lot of grammatical awkwardness and just plain confusing sentences in dialogue exchanged throughout this first volume. If you're interested in reading this series, be aware that that's a bit more prevalent here than in some other titles originally published by Tokyopop.
Beyond that, I enjoyed re-reading this. This is definitely a fluffy title with a slight mystery edge to it, and it's fun to have revisited. (Naturally I hope to finish tracking down and reading the rest of the volumes, because it's worth the read.)