I first got into Zombie-Loan quite a while ago and watched a few episodes of the anime then forgot about it. Then later, I remembered about it again and watched the rest of the anime. By that time, I'd started getting into manga more than anime, so I started reading the manga. The anime is very close to the manga, no fillers or anything. As I read the manga more, I came to love it more.
The story can get a bit complicated at parts, but overall it's really exciting, and often chapters end on a cliffhanger, leaving me waiting eagerly for the next chapter to be released. There are hints of romance, although they're quite subtle, but there is some obvious romance between Chika and Michiru (although Chika is a bit too dense to realise his crush on her) and some 'romance' between Shito and Michiru. I think Shito thinks of Michiru as a motherly figure, but maybe that's just me.
The characters are also well thought out, the main characters are likeable and the 'bad guys' are devilish and evil. As I said above, the hints of affection between the characters is one of my favourite aspects of ZL. There's also the A-Loan, Z-Loan's rivals who start out being annoying, but eventually I started to like them too. The more the story progresses, the more secrets of the characters are revealed.
The art is great, I enjoy reading ZL and seeing Chika's cheeky face. :P The drawings are really good, far better than anything I could draw, and a lot better than some of the other mangas I've read.
To put it simply, I think Zombie-Loan is amazing. I reccomend it to anyone who likes supernatural manga, or for anyone who likes manga with less shoujo-ish romance.