Mob Psycho 100: Dai Ikkai Rei toka Soudansho Ian Ryokou - Kokoro Mitasu Iyashi no Tabi

モブサイコ100 第一回霊とか相談所慰安旅行~ココロ満たす癒やしの旅~

The staff of the Spirits and Such Consultation Office—Arataka Reigen, Shigeo "Mob" Kageyama, Ritsu Kageyama, Katsuya Serizawa, and the spirit Ekubo—head to the Zebra Prefecture for a relaxing hot spring vacation. Their all-expenses-paid trip is sponsored by the owner of the Ibogami Hot Springs, who has asked Reigen to investigate claims of paranormal activity in the area.

On the train ride to the inn, the exhausted Reigen and Serizawa quickly fall asleep, only to wake up and discover that they have been transported to a ghostly parallel world! Bewildered about how they got there, Reigen and Serizawa must find a way to escape in time to enjoy their day off.

(Source: MAL Rewrite)