Zombie-Loan, Kuroshitsuji Recommendations
Square Enix worked on both manga.
In both you'll find eye-patches, Shinigami, contracts, death, a dark mood, and great art.
But the most notable similarities are those between the characters: in both series we have the usually clumsy meganekko (Michiru/Meilin), the gay man who provides some comedy (Hakka/Grell), the always calm and kinda tedious Chinese guy whose eyes are constantly shut (Toho/Lau), the emotionless pretty girl (Kuze/Ranmao), the weird and non-human ferryman/grave-digger (Bekko/Undertaker), the cute and cheerful shota boy (Yuta/Finnian), and even the domesticated wolf (Raika/Pluto).
That said, Zombie Loan is overall way better.
Kuroshitsuji (Black Butler) and Zombie-Loan adapts a story that associates themes related to death. There are supernatural forces that exists in both series that becomes a powerful source of mystery. The main protagonist also display unnatural abilities. Along with their presence, there is a lot of focus on relationship building. Expect story development and characterization as each chapter shows the readers more and more about the main characters.