Amagoushi no Yakata: Portable - Ichiyanagi Nagomu, Saisho no Junan

“Can Nagomu solve a murder case by the end of the seventh day? Can he stop the culprit from taking full revenge?”

This is an adventure game based on a classical mystery novel. Running out of petrol and lost in the mountains on a stormy night, Ichiyanagi Nagomu, a university student has no choice but to leave his car and ask for help from the nearest mansion within the woods. However, a shock is waiting for him in that dark night. He finds the corpse of a middle age man lying in the rain at the backyard of the mansion. Without any time to recover from his shock, somebody sneaks up behind him and attacks him.

When he wakes up, he is in the company of a troop of actors and actresses there to train for new play written by the famous play-writer Boushiya, and being mistaken as the ninth actor, nobody believed what Nagomu saw at the backyard. Because of the injuries he has suffered earlier and the storm still raging outside, there is no alternative for him but stay in the mansion.

Later that night, the troop and Nagomu discovers a message that reads "Revenge" in the green house. Afterwards the troop realized that the tires of their cars have all been punctured and there is no escape route. Fear permeates the air that night, but that is only the beginning of their ordeals. The next day, one of the actors is found dead with his corpse arranged in a peculiar way.

Panic erupts when a landslide cuts the mansion off from the rest of the world and being overpowered by fear, the only thing the actors and actresses think of is to protect themselves. This leaves the case solely upon Nagomu's shoulders since he is the only one unrelated to the act of "revenge".

This is an adventure game based on a classical mystery novel.