If you're looking for manga similar to Mou Hitotsu no Monster: The Investigative Report (Light Novel), you might like these titles.
In the café Anteiku, where Ghouls gather, danger and the possibility of discovery loom. Yoshimura, the café’s owner, is harboring suspicions about a certain someone. What sort of darkness will that person bring to those who hunt and those who are hunted?
Two boys lived in a village: Yoshiki and Hikaru. The two did everything together...until the day Hikaru was encompassed by a mysterious light. That was when everything changed—Hikaru most of all. Yoshiki still wishes from the bottom of his heart to always stay by his side...but is there even a Hikaru left to be with?
Two men work together to reveal the outrageous falsification of the history of a German town, Hammelburg, which took place eight hundred years ago.
Touko-chan is a Japanese woman who works as a writer, and currently lives in Berlin with her cat, Mugi-kun. In this flat, stone-paved city surrounded by greenery, she occasionally goes out on picnics and figures out how to make the Japanese food she misses, as well as first-rate afternoon snacks using local ingredients. It's nothing special, but reading this happy and humorous illustrated day-by-day journal of living in another country is sure to make your heart swoon.
Tomoko's parents have to stay in Germany for three years because of their job so she move to her uncle's and join Saint Alice High School where students must follow some weird rules. Only some of the best students, the nobles, are relieved of this, especially the queen, Himiko, the president of the student committee. There are two people who rebel, Zero, the mysterious thief and Kid the pirate. They fight against nobility and help the students.