If you're looking for manga similar to Kamichama Karin, you might like these titles. All recommendations are made by Anime-Planet users like you!
This book is also by Koge-Donbo. Her art is amazing. Both stores have some sort of tragedy in them and are both romantic and funny. You'll love this manga.
Since they're by the same author, they have similar storylines (girl-meets-boy [KK] or boy-meets-girl [PT]) and art (characters with detailed, floating hair; fancy dresses; and crazy-huge eyes). They both are magical girl tales in their fullest, with the fights that consist of protagonist being beat up for 99% of them before he/she uses one attack to blow up enemy. Overall, they're both pretty darn cute.