The manga on this list meets the requirement of having the Romance, Comedy and Supernatural tag. I also find this manga to be interesting and great to read if you are looking for one. Also I feel these manga may unknown and need more attention.
Monster Musume no Iru Nichijou:
An interesting manga were the main protagonist is confronted with living with several different species of Monster Girls and their romantic feelings for him. The world of the manga has the reality of monsters and other species of myth exist. It is fun to see the personality of each girl and the designs and stories are fun to read.
Jitsu Wa Watashi Wa:
In this manga a young boy finds out that the girl he like in class is a Vampire. Knowing her secret he keeps it, letting her stay in the school hoping to build the relationship with her. It is a fun romantic comedy and the addition of different creatures and girls made the manga more interesting.
This manga does not necessarily have an overt romantic comedy feeling, though these elements are present. The series focuses on a demon slaying family and the heiress, with her two shape-shifting wolves. The series has a charm to it though it feels rushed. It is a fun read and a good story.
Super Dreadnought Girl 4946:
A girl transfer to this boys school, the twist she is a giant and fights giant monster for the government. This series is fun and heart-warming, making me want to read more. The characters are fun and the story is thought out well, with the romance enjoyable.
Otome to Meteor:
A cute story, a girl is born with incredibly bad luck, until one day she is confronted by an alien prince that tells her that she is his destined one he is meant to be with. The series is gun and enjoyable with the development of the prince as interesting and fun to watch.
I find these manga all enjoyable and would recommend you read them. Though I do not promise that you will enjoy it, I can tell you I find them interesting. Maybe these are popular and well known and I just found them by accident, I feel they need more attention. Also if you don’t like romance comedies, you will probably not like these manga, however that is not a guarantee.
I want to thank all of my followers and friends and I will continue to do this for as long I believe I have interesting ideas. Thank you again and have a great day.