It's an optimistic, happy manga about a ghost. Her name's Kana. Years ago, she killed herself in a fairly disgusting way and was only discovered quite some time later when a neighbour noticed the smell. The body had become unidentifiable. Now, though, she doesn't really remember anything about all that. She's cheerfully haunting her old apartment and falling in love with a boy called Daikichi.
There isn't much plot. It's just about two young people who love being together. They also learn that Daikichi can touch Kana, so there are lots of sex scenes and you'll find this short series in the hentai section of manga stores. It doesn't read like porn, though. It's a romantic story that happens to contain explicit content.
Kana's great. She gets excited about simple things. Ch.1: beer. Ch.2: TV. She has great facial expressions, e.g. when trying to persuade Daikichi to buy super-hot-spicy. At the same time, though, she's also capable of being weird and supernatural. That slime she covers him with... is that ectoplasm? (They clean and tidy up the apartment.) In the chapter with the forgotten grave, she shrinks. You can use her as a beer cooler by putting your beer can between her breasts, while you can do things with her that would be impossible with a living girl. (Putting your hands inside your partner's breast. Crumbs.)
"I know. Now I remember. This is how it feels to be alive!"
...as her body splashes, as if she's water and someone threw a rock in her.
Or, alternatively, there's a chapter where they've been fighting, so "Kana got angry, went in the wall and refused to come out." It's surreal, silly and quite cute. He offers her beer, which she drinks while his back is turned. He writes "idiot" and "hothead" on her bit of the wall, so... "When I opened my eyes the next morning, she had taken her revenge. My entire body was covered in bloody handprints."
There are other characters, e.g. Utako, another "abandoned" girl who moves into the apartment with a guitar and almost nothing else. The manga's capable of touching on despair and darker emotions, but ultimately it's a story about learning that it's never too late to be happy, live and love. It's funny, with cute goofing. Recommended, if you don't mind sex scenes.