This is my first recommendation so if i make a mistake please excuse me ^^.
When i read Shigatsu wa kimi no uso it reminded me a lot of kagen no tsuki.Both manga will make you laugh and cry and feel really strange like life is so unfair but at the same time so beautiful.I really cant put the right words for what i felt when i read these two.Maybe because they were so realistic i felt emptiness and unfairness.In Shigatsu there is a 'lie' and in Kagen there is a 'secret' lets say.Music is similar in both manga.Also some quotes or pages will make you cry or even shudder everytime you see them.You should give it a try!
Like the fading moon,
ruining the darkness,
I sing something,
I pray for something,
As I lose the sun that is you. -Kagen no Tsuki
After the first note resonated through the hall, You became everything I yearn for. -Shigatsu wa Kimi no Uso
Both manga feature a similar setting as the protagonist becomes involved with a ghost. Kagen no Tsuki differs with a larger focus on mystery and investigation as its characters attempt to uncover who the ghost is. While Natsuyuki Rendezvous focuses more on romance and drama as a love triangle forms as the ghost is the heroines dead husband. Overall, both are solid bittersweet reads recommended for anyone who enjoys stories about helping and interacting with a ghost.
Both tittles will appeal to fans of romance and mystery. Omae ga Sekai o Kowashitai Nara has a much sadder tone and it is even more supernatural than Kagen no Tsuki, but I believe that a reader who enjoyed one will like the other - especially if what drew you in is solving the puzzle that the plot offers. Not for those who wish for a happily-ever-after-ending.
Both are drama, romance, mystery and supernatural. Extremely similar feel. Each chapter feature a different character's point of view, and how they may contrast between each other. Also, both series are about a group of people trying to understand and know more about supernatural events where reality and dream, present and past, overlap each other, and the deep effects this may have on their own lives.
The only difference is the lenght, but if you liked one of these series, there is a great chance you'll enjoy the other.
Also one of Ai Yazawa's work, Nana holds one or two references to Kagen no Tsuki. Both stories have love and music in them, though Kagen no Tsuki is also paranormal and holds a secret you find out at the end. Nana is more realistic and focuses it's story more on the feelings of the characters. Kagen is much shorter than Nana, but both are very enjoyable.
These two are both mysterious stories involving romance and supernatural without it getting annoying. The stories are very different and interesting, the character development is great and they both leave a bitter-sweet feeling after u finish reading these.
It's also manga by brilliant Ai Yazawa. She was making these two comics at the same time. They have diffrent plot but same characters and atmosphere . Paradise Kiss is more realistic but both are telling us about true feeling between people.