Gogogogo-Go-Ghost!, Vol. 4 (manga)

Heartbroken office worker Ushiro and her glamorous guardian spirit Masako have been chasing their philandering foe Yuu-senpai—and that's put them on a collision course with his dangerous new girlfriend! Masako has never let Ushiro down yet, but this latest target seems to be putting up some surprising spiritual resistance… With dark truths rising to the surface all around her, will our heroine find new comrades in revenge, or rivals beyond her ken!?