KOTAMON Cereal Boxes — How to Get & Open Them
Source 1 — trash piles
Boxes spawn randomly inside garbage heaps, like figurines and audiotapes. The August 22, 2026 patch explicitly made them "much more common", after players calculated the old rate would take (in the developer's words) "13,486 years" to hit the ten-box achievement. Search every fresh heap before recycling its ordinary trash.
Source 2 — Jenny's shop ($10,000)
Once all your stats are maxed (see upgrades), Jenny sells a cereal box for $10,000. That price is the post-patch number from the official Aug 22 note — older community posts quoting $50,000 describe the pre-patch build.
Why boxes matter
- The Steam store confirms a box can hold a super-rare foil card — the only officially named foil source. Full foil strategy: foil card guide.
- Two achievements hang on them: Just Don't Eat It! (open 1) and Gacha Addiction (open 10) — see all achievements.
- The game's whole premise starts with one: the sister's super-rare card came out of a cereal box.
Cereal Box FAQ
How do I open a cereal box?
Interact with the box in your inventory the way the sister does in the intro — opening one is the "Just Don't Eat It!" achievement, and opening ten is "Gacha Addiction". The prize inside can include a super-rare foil card.
What are the odds of a foil card?
The developer has not published drop rates — only that boxes "can contain" a super-rare foil card, and that box spawn chance was raised in the August 22 patch. Treat any exact percentage you see elsewhere as invented.
Why is the shop box so expensive?
It used to be far worse — the August 22 note jokes that players who haven't maxed their stats "won't want to know how much it used to cost". At $10,000 post-patch it is a reliable foil source for a maxed character.