Masaki Sachiko is a bit of an odd character from what you've seen of her. She runs her group as a business, and is undoubtedly very intelligent, but her ruthless businesswoman façade could really use some work. She even tells you straight up what her unique ability is.
Contracts made by her are magically binding. You must agree to the contract of your own will without being forced, but once it is agreed to both sides are bound to the spirit of the contract as they understood it regardless of whether they originally intended to follow through or not.
I was standing in the shower when the realization hit me: Mami
desperately needs some actual businesspeople in her employ because she read this all wrong. Sachiko revealing her unique ability straight up
is her being a ruthless businesswoman.
In one feel swoop she makes us aware of a
very valuable and quite possibly
unique service she can provide us without actually
offering said service to us. If she plays her cards right she could very well become
untouchable.
Contracts are
fundamental to the way humans interact. The majority of all contracts are verbal rather then written but more and more the latter is becoming prevalent thanks to the ease of production and evidentiary nature of a written contract. Being able to guaranty they'll be obeyed in both letter and spirit is
indescribably valuable.
Just imagine how useful her contracts would be to other factions, hell even our own to a lesser extant, in guarantying every new member is loyal. It opens up all sorts of new opportunities. That's not even getting into things like trade contracts, sharecropping contracts, mutual defense pacts, and all the
millions of other things you can make a contract over.
Even putting all that aside simply being able to hire mundane office workers would be a
godsend for the Serene. We have massive amounts of paperwork being generated that requires serious girlpower to process. Imagine how much more efficient and effective everything would be if we could hire actual statisticians to crunch data, accountants to do our books/taxes, secretaries to ensure important information gets to everyone who needs to know, ect.
Now that I think I've sufficiently proven just how valuable Sachiko's power is let's get into how her not offering it to us is a great move for her. Put simply it means that
we have to go to
her and
request the service rather then accept her offer. That puts her in a position of power in negotiating, although she's already in a strong one from the sheer value, and makes justifying rip-off rates a lot easier because she can sell it as a "special" service we've "specifically requested" rather then a standard one she offers.
As for how exactly it's a rip off? Well I suppose it really depends on just how much it costs her magically (if at all) and time wise to create these contracts. We have no idea the cube cost but a contract can
easily be written up in
minutes since she doesn't have to include all the legalese loophole closing normal contracts require since it works on the spirit the contract was written on not just the words themselves. That incidentally is what she was showing off, yes that was showing off, by having those sample one page documents in (fairly) plain
English Japanese. The time is likely even
faster since there is a good chance she can probably type them, hand written contracts would look
very odd to potential employees, and even if she can't template contracts are a thing so she could easily whip up dozens of those and only fill in the details as needed.
The magical cost could be answered if we knew if those sample contracts were samples in the sense they were a non-binding copy of the contract (IE: documents with the words "Sample Not Valid" watermarked throughout) or if they were samples in the
free sample sense. If it's the latter then her contracts are cheap enough to mass produce.
For straightforward contracts, and especially template ones like Sachiko's employee contract, I'm guessing she'd be charging a grand or two plus expenses, IE: grief cubes depending upon how much of a drain this is, per contract. It's notably higher then what you'd get for standardized contracts, that's more in the $500 or less range from my googling, which emphasizes her value but not too high as to limit her target market.
When you consider she can potentially service basically every notable faction in Japan and consider just how many contracts they are likely to go through, for example the USA over an 8 year period had an average turnover rate of 3.3%
per month, on a regular basis that is easily enough to become incredibly rich. Even more when you realize she'll likely try and set herself, and by extension her corporation, as neutral mediators through which conflicts can be resolved and (most importantly) those resolutions be
enforced.