It has comedy moments and it's pace is gentle. It does not take itself too seriously. It is primarily focused around the lives of 2 teenagers who go to the same school together;
Mamiya Sakura: A fairly quiet teenage girl who has a "go with the flow" attitude. She is quite perceptive (and reasonably popular) and in many regards, totally average for a teenage girl except for one thing: When a child she gained an ability (which she keeps secret) to see spirits and other otherworldly beings. One day she discovers that one of her classmates (Rokudou Rinne) is a Shinigami.
Rokudou Rinne: An impoverished (and fairly serious in nature) teenage guy who is also secretly a Shinigami. Although skilled at his work of sending stray souls to the afterlife (and outwitting & battling supernatural beings), he is also always desperately trying to pay off a large financial debt (which is not his fault but which he is held responsible for none the less). He has a good heart (and strong sense of right and wrong) but money is often a huge motivator or influencing factor in how he deals with situations.
Events of course end up conspiring that the two of them have to unite and they end up going on many adventures together (which each episode revolves around).
If you are looking for...
1. An anime with a gripping story line.
2. Strong characters with lots of development.
3. An anime with a strong sense of direction.
4. An anime with lots of fan service.
5. An anime with epic fight scenes between supernatural beings.
6. An anime with a passionate and heart-rending romance between its main characters.
...Then Kyoukai no Rinne is NOT for you (and if you watched the anime while hoping for any of these things, you would probably end up feeling rather disappointed and would rate the anime quite poorly).
However.
If you are looking for...
1. A anime with a relaxed story line.
2. An anime which doesn't take itself too seriously.
3. An anime which has comedy moments (but which doesn't try too hard to be funny).
4. An anime that is ideal to watch when you want to unwind & chill out.
5. An anime with a certain old school vibe about it (but which has the pros of being modern and visually appealing)
6. An anime which has a different story each episode (VS long one consistent plot arch).
Etc, then I would strongly Kyoukai no Rinne for you!
This anime is not a masterpiece. However I found it very enjoyable and relaxing to watch (and the series is in fact one of my top favorite anime's). It is also a successful anime with not only a generous 25 episodes in its 1st season, but (as I type) a second season (also spanning 25 episodes) is now being aired too.
Although Kyoukai no Rinne is marketed as being a Shonen anime (Shonen of course being anime/manga primarily intended for boys between the ages of 8 to 18) I could see just as many girls enjoying this anime (if not even more so) and would say that overall, its appeal is very broad in both its gender and age range (I am an adult and yet I still found this anime entertaining & very enjoyable to watch).
