This is a bit of a story requirement, but can be done in many different ways, I suppose.
1) Sam, one of the first residents to move back to the town, has a soft spot for Softwood Lumber. You can keep giving him one a day to increase his friendship. You can tell the status of the friendship based on the notes near his name when you talk to him. When one note is full, you should have this requirement met.
2) Sally, Naomi's daughter, likes Bamboo Shoots. Given how early on in the game you can find them, you could always give her one every time you see her (daily, not EVERY time). This may take longer, but it is another option at least.
3) After opening the mines and helping Gus, you should find a Magentocrystal on the first floor of the mine. When you go to bed that night, you will go to place it on the floor. Rowan will come by the next day and suggest you keep polishing/rubbing the crystal daily. Once a few days pass, a Gem Sprite should be born out of the crystal, complete with a full level note.