NOTES
Quiet notes from working and living in Tokyo, and from making small tools along the way.
Hiding a sheet in Excel does not take it out of the file. We built a workbook with a hidden sheet, a very hidden sheet, hidden rows and columns, comments and author details, then compared the contents before and after hiding. Nothing had been removed. Here is what to check before you attach an .xlsx.
PDF metadata can be read in Firefox from Document Properties, with nothing to install. Here are the steps and the fields worth reading, followed by what we found in ten real PDFs — an author name in two of them, and the name of the software in nine.
One prompt does not turn into a published extension. After shipping eight of them, here is the order I actually work in — defining the annoyance, cutting the scope, splitting the build, checking permissions myself, and getting through Chrome Web Store review.
Setting a Word document to show no markup does not take the tracked changes out of the file. We built two files, one with markup hidden and one without, and compared what was actually inside. Nothing had been removed. Here is what to check before you attach a .docx.
A Chrome extension's details page has two separate sections, Permissions and Site access. Across our own seven extensions the Permissions section was empty every time, so the only thing left to read was Site access. Where the broad warning actually comes from, and why identical wording can mean opposite things.
How common are misdirected emails? I read three public Japanese sources — the regulator's annual report, a survey of listed companies, and an expert threat ranking — and found no single number, just three different pictures of the same mistake.
When you paste text into an AI chat you want a summary or a cleaner draft, not to hand over someone's details. The details are in there anyway, usually at the edges. Why I added a single pause before sending, and why the tool stops short of deciding for you.
The front page I built with AI had everything a site is supposed to have. It was calm, it was clear, and if you covered the logo you could not tell whose it was. What I think caused that, and what I changed when I rebuilt it.
My home address was sitting at the bottom of my own Chrome Web Store listing. The cause was declaring the publisher account a trader; switching to non-trader removed it. What the declaration actually asks, and why choosing non-trader is not a privacy setting.
The rejection was about the store listing, not the code or the permissions. Naming every supported service felt like scope to me; from the outside it was indistinguishable from keyword stuffing. The five-item guidance in the spam FAQ, what I cut, and how I rewrote the description.
What actually runs where in a Manifest V3 Chrome extension. The file layout, what manifest.json tells the browser, the isolated world between content scripts and the page, the service worker that does not stay running, messaging, and permission design — with short code examples.
Every Legacy Tools product is a Chrome extension rather than a web service. Not because extensions are technically superior — I wanted to place small safety features inside the browser people already use, starting with my aging parents. On that choice, and on not automating safety too far.
Chrome can do more than display websites. Extensions add small features to the browser you already use, and the Chrome Web Store is where you find them. How installing works, and what I check before adding one, from someone who publishes extensions.
Generative AI has shortened the distance between noticing a small inconvenience and building working software. How I split the work between ChatGPT and Claude Code, why larger software still feels out of reach, and how I decide how small a tool should be.
A snapshot of the tools I use as of July 2026. The same AI plays a different role depending on where it sits — chat, CLI, or design. The actual steps of shipping one Chrome extension, and the decisions that stay with a person.
No notes here yet.
