Alongside the v0.4.0 update, the inZOI team has published a guide to the game's first Halloween season. The pitch is that it has two faces: pumpkin farming by day, and trick-or-treaters and ghost fish by night.
Trick or Treat
Place a Halloween Candy Basket on your property and children will visit every night. Talk to them, hand out candy, and you'll get Halloween-themed items in return — and the type of candy you give can change what you get back, so it's worth experimenting rather than handing out the same thing each time.
Pumpkins first
Preparing for the season starts with farming. Grow the new pumpkin crop yourself, or buy pumpkins from the Farming Supply Store or Pocket Market. Process them at a crafting table to carve jack-o'-lanterns, which double as wearable hats and house decorations.
Unlockable rewards
There are two separate pools, earned two different ways:
Character items come from Canvas events. Search for the Palet account on Canvas — the content manager from AR Company — to pick up the special Halloween costumes. You get 4 sets, 1 pair of shoes, 1 pair of socks, 2 hats, and 2 accessories.
Restart the game after downloading, or the items won't show up in Character Studio.
Build items come from taking part in the in-game Trick or Treat events: 15 Living Room, 39 Common, and 4 Outdoor items.
Ghost fishing
After dark, faintly glowing ghost fish appear in the sea and lakes. They're caught the same way as regular fish but are rare — the patch notes narrow the window to 6 PM–6 AM during the Halloween season. Put them in a fish tank for the atmosphere, complete the collection, or just sell them for Meow.
Read the full announcement: Official inZOI Website