The investigation half of TSUMIMI TIME is where most players lose time, and it is almost entirely a matter of knowing where to look. The mechanics are simple - you learn keywords during streams and then search with them - but the search space is wide and the obvious route is not the efficient one.
You do not start with a list of search terms. Keywords are learned during streams - a phrase Tsumimi says, something visible on screen, a name a viewer drops in chat. The keyword you need for the next step of the puzzle is almost always something you have already seen and failed to note down. Pay attention during the broadcast, even when nothing seems to be happening.
The official guidance names four categories of source: social media, fan sites, maps, and search results. Each contains a different kind of information, and the game expects you to move between them:
This is the specific instruction the developers give, and it is the one that matters most. The game's own guidance says to be sure to check replies to posts and location details. The clue that unblocks the chain is frequently one reply down or one field deep - the top of the post is context, the reply is the answer.
Everything collected is reviewable in Investigation Files. This is where raw information becomes a deduction: the files hold what you found, and the ending is determined by which fragments you manage to connect before the run ends. A clue collected but never linked is a clue that will not help you.
Spoiler-light list of the recurring clue families, so you know what you are looking at when you find it:
The chains connect: the triangle mark leads to the faith and the village, the village explains the ritual and the tunnel, the mannequin ties the physical evidence together, and the missing-person thread - Mashiro and Hinanon - sits on top of all of it.