Tonari no Obake-san  

My Ghost Neighbour, Kagefumi: Kasanaru Toki, Aozora Gakuen e Youkoso, となりのオバケさん

Once entering high school, Nanami gained independence and started living on her own. Nearby lived a young man named Niji, who exuded an enigmatic vibe both inside and out. Gradually, Nanami found herself drawn to him until she uncovered the astonishing secret he had been concealing.