Tsuika-shiryou (追加資料) refers to ‘additional materials’ or ‘supplemental documentation’ requested during a project or negotiation. In Japan, this isn’t just paperwork—it is often a barometer for how much your client trusts your preparation.
When I first moved to Tokyo, I treated requests for tsuika-shiryou as simple administrative tasks. My manager would ask, ‘Can you prepare some tsuika-shiryou for the meeting tomorrow?’ and I’d print a few extra charts. I was wrong. In the Japanese corporate world, this phrase is rarely about ‘extra’ fluff; it is a signal that your initial presentation left a gap that needs filling before a final decision can be made.
The Psychology Behind the Request
When a Japanese partner asks for tsuika-shiryou, they aren’t necessarily looking for more data for the sake of it. Often, it implies they need ammunition to sell your idea to their own superiors. By providing high-quality supplemental data, you are actively participating in their nemawashi (consensus-building) process.
“If you provide exactly what was asked for, you are a clerk. If you provide the data they need to clear the internal hurdles they haven’t told you about yet, you are a partner.”
Common Mistakes Foreigners Make
The most common error is ignoring the ‘need for speed’ or, conversely, over-delivering irrelevant fluff. If you take too long to send these materials, you might be perceived as lacking efficiency. Worse, if you send a 50-page document when they only needed one specific figure, you disrupt their ability to present your case concisely.
Pro-Tip: Always confirm the specific focus of the requested material. Ask, ‘Dono yō na ten o jūten ni matomereba yoroshii deshō ka?‘ (Which points should I focus on when compiling this?). This prevents you from wasting time on data that doesn’t serve the decision-maker.
Slang and Nuanced Usage
While tsuika-shiryou is the standard business term, you might hear colleagues refer to it casually as tsuika (add-ons) when internalizing the workload. If a project is constantly requiring these, it might be referred to as tsuika-tsuika—a sign that the project scope is drifting. Be careful; if you hear this, it’s time to re-align your uchi-awase meetings to ensure the project requirements are locked in.
Final Thoughts
Mastering the art of providing effective supplemental material is about anticipation. Don’t wait for them to ask. If you identify a weak point in your own proposal, offer the tsuika-shiryou proactively. It shows a level of professionalism that builds the ‘Uchi’ (insider) bond required for long-term success in Japan.
