This guide explains where event stickers come from, how to handle duplicates, and whether an unclaimed collection reward disappears.
Quick answer
The official announcement confirms that the Vitality Growth Challenge runs from August 29, 2026 at 06:00 to September 14 at 06:00. Completing event missions grants a random sticker from a theme that is currently open. Duplicate stickers can be gifted to other Developers, and each set awards a reward after you collect the required number of stickers.
The most efficient order is to finish the available daily missions, check both missing and duplicate stickers, and then arrange exchanges with reliable friends. Do not immediately give away the first duplicate you receive, because later themes and your friends’ needs may change.
Where event stickers come from
The main method explicitly described by the official notice is the event mission list. A completed mission awards one random sticker from a currently available theme, so there is no confirmed one-to-one link between a particular mission and a particular sticker.
Use this routine after logging in:
- Open the event page and review today’s missions and currently unlocked themes.
- Prioritize missions with a deadline or a multiplayer requirement.
- Claim each sticker and verify it in the collection screen instead of relying only on the reward pop-up.
- Record the number or name of each missing sticker so that exchange requests are precise.
Random distribution naturally creates short-term duplicates. A duplicate does not by itself mean that the mission failed. The gifting feature exists specifically to help players redistribute extra stickers.
How to exchange duplicate stickers
The official wording describes gifting, not an automated one-for-one trade. It also sets a daily limit of 5 stickers sent to the same recipient. The system does not force that recipient to send anything back.
Use these precautions:
- Confirm the exact missing and duplicate stickers on both sides before sending.
- Agree on a small number at a time and verify delivery immediately.
- Prefer long-term friends or members of a stable community.
- Never provide an account password, verification code, or off-platform payment for an exchange.
- After reaching the daily limit of 5 gifts to one person, wait until the next day rather than treating the limit as a bug.
Claim the reward after completing a set
Once a sticker set reaches its required total, claim the corresponding reward from the event page. The official notice says that a reward left unclaimed on the day it becomes available will be mailed the next day. Any accumulated reward still unclaimed when the event ends will also be sent by mail.
This delivery rule reduces the loss caused by forgetting to tap the claim button, but manual collection is still safer. Check mailbox capacity and any mail expiry notice. A mailed reward does not mean that missing stickers will be filled automatically.
Three common problems
| Problem | What to check |
|---|---|
| A completed mission did not appear to give a sticker | Confirm the mission reward was manually claimed, inspect the collection page, and reopen the event |
| You keep receiving duplicates | Random rewards can repeat; sort duplicates and use the gifting feature |
| You forgot to claim a completed-set reward | Check in-game mail the next day; contact official support if it is still absent after the event |
A five-minute daily sorting method
After completing missions, divide your collection into three lists: complete, missing, and giftable. Prioritize themes that need only one or two more stickers before working on sets with large gaps. Send friends a direct missing-sticker list. This reduces back-and-forth messages and helps prevent you from gifting your final copy by mistake.
Patch-risk note
This guide was verified on September 1, 2026, while the event was active. Missions, theme-release timing, rewards, and menu locations may be adjusted by the developer, so use the current event screen as the final authority. Forum guides and player exchange posts are demand signals only; they cannot establish an official fixed drop location for a particular sticker.