Yuri Tantei Yurianzu

Yuri Tantei Yurianzu (百合探偵ユリアンズ) is a manga series by Noboru Kimura with illustrations by Shuu Hirose. It was serialized in Champion RED.

Plot
Amou Academy is an enormous educational establishment that boasts of 200,000 students and a gigantic campus that is actually its own city. Sakai Anzu is one of two members of the Detective agency operating on campus and is a normal high school girl. On the other hand, the other member, Yuri, is something out of this world. Yuri normally looks like a young girl but she is able to use sorcery to transform herself into a more mature appearance where she gains the ability to solve mysteries and crimes.