Purchase the Story of Seasons: Pioneers of Olive Town expansion pass and befriend Mikey and Cindy to investigate the mysterious occurrences in Olive Town.
Purchase Expansion Pass
Before you can unlock the Mystery Files, you must purchase the Story of Seasons: Pioneers of Olive Town Expansion Pass.
Befriend Mikey and Cindy
Before you can start investigating mysteries, you need a certain friendship level with Mikey and Cindy.
Develop the Town
Before you can start the Mystery Files scenario, you have to develop the town to a certain level. As you progress in the game, Victor may visit at the start of the day to tell you about new Town Requests in the Town Hall. Be sure to visit the Town Hall and check the bulletin board for Town Requests (different from requests from individuals). The more requests you fulfill, the higher the town's development will go.
Investigate the Four Mysteries
When you have met the above conditions, there will be a cutscene when you go into town. Victor mentions mysterious occurrences in the park, at the beach, on the wall of the Gull's Rest Hotel, and something scaring the animals. Your first destination is the park.
Investigate the Park Mystery
The next time you go to the park, you find Jack, who tells you about the mysterious circles in the park. After the cutscene, there will be a new Mystery Files request on the bulletin board in the Town Hall.
Turn In Yogurt
The first request is 1 Yogurt. You will need to get Milk, either from a cow on your farm or from Norman's Grocery Store, and then you will need to use a Yogurt Maker to turn the milk into yogurt. You will learn the Yogurt Maker recipe after you reach Animal Care Lv.3.
Solve the Park Mystery
After you turn in the yogurt, the next time you go into town, there will be a cutscene. Afterward, there will be new Mystery Files requests in the Town Hall. You need to turn in 1 bag of Fodder Seeds and 1 Lumber.
Investigate the Beach Mystery
The next time you go into Olive Town, you will hear from Marcos about the beach mystery. Afterward, there will be a request in the Town Hall for 1 Solid Lumber.
Solve the Beach Mystery
The next time you visit Olive Town, there will be a cutscene. Afterward, the next request at the Town Hall is for 1 hot milk. The recipe is learned at Cooking Lv. 4.
Investigate the Café Mystery
In Olive Town, there will be another cutscene, this time about the mysterious shadow in the Café. The next request in the Town Hall is for 1 Floral Perfume. You can put flowers into an Essence Maker to make 3 Floral Essence, and take them to the Flower Shop and have Nguyen turn them into a Floral Perfume.
Solve the Café Mystery
Investigate the Mystery of the Scared Animals
Solve the Mystery of the Scared Animals
The Final Mystery
After you turn in the above items, there will be a cutscene when you leave the Town Hall. Afterward, a new outfit is unlocked in the Beauty Salon, and with that, the Olive Town Mystery Files scenario is complete!