Shinrei Tantei Yakumo: Akai Hitomi wa Shitteiru

Based on the novel by Kaminaga Manabu. Shinrei Tantei Yakumo (Psychic Detective Yakumo) tells a story about a college student, Saitou Yakumo, who was born with different eye colors. His red left eye gave him the special ability to see ghosts and spirits. He believes ghosts and spirits are bound to earth because of a certain 'cause' and simply by eliminating that 'cause', those spirits will rest in peace. Being asked for help by Ozawa Haruka, together they began the investigation.

(Source: Fateful Encounters)

Included one-shot:
Volume 1: Mail x Tomodachi