Mob Psycho 100 : The First Spirits and Such Company Trip ~A Journey that Mends the Heart and Heals the Soul~

Mob, Reigen, Dimple, and the newest member of the Spirits and Such Consultation Office staff, Serizawa, take a trip up to a secluded hot spring called Ibogami Hot Springs. Ritsu and Teru also join in on this trip. Reigen happened to get a request from the matron there to discover the truth behind the strange rumors going around there and save the inn. On their way there, Reigen and Serizawa start nodding off on the train and somehow get sucked into a parallel world. (Crunchyroll, edited)