Ottori Sousa

The story is about a Detective named Akiba who crosses paths with a high school idol named Mizuho. He was assigned to protect her. But he's also a young detective and a bit unorthodox. For the first two volumes Mizuho ends up getting involved in Akiba's other cases but eventually it progresses into a friendship, and eventually a relationship.

(Source: MU)

Included one-shots:
Volume 7: Arcana (pilot)
Volume 10: Silent