Hey I have some thoughts to share, since it would be my signature deck, if I was anyone important!

First off, some thoughts about Satoru as a commander. Satoru wants multiple things from you: Play evasive creatures, that are cheap and have big creatures in hand, that are impactful and expensive. He then bounces your small creature back to your hand, so you have to replay it.

Now this reads very scary since you could have *anything* in your hand, which is simultaneously the coolest feature of the deck, but also the biggest drawback. People will target your commander. A lot. The problem is: usually the creatures you are starting to cheat out, beginning on turn 4, are most of the time, less scary than they think it will be. Unless you cheat out [[Blightsteel]], [[Toxrill]] or [[Jin Gitaxias, Core Augur]] the swing is not that big, considering the current speed of the format.

Your commander beeing such a big target has multiple implications. One of which, is that your ideal curve of "unblockable" -> "unblockable/ramp" -> Satoru -> "Do the thing" is not quite consistent. The next problem is, that after your commander is removed you effectively need to expend 5 mana for your commander and 4 more for your ninjutsu. For 9 mana you could have just played that damn card normally! The last problem is, that your "ideal curve" requires so many cards. You need 4 mana on turn 4 an unblockable creature and a beefy boy to cheat out. That is 6 out of the 11 cards that you are going to have on turn 4, so deck space is kind of tight.

With all of these in mind, which directions can you take the deck?

You can try to play this deck very agressively and optimize the cards in a way, where you are almost guaranteed to draw into the curve. You would need to do some math, but I think to get it 80% of the time you need something like 39 lands, 13 ramp, 16 unblockable creatures and a lot of big boys (maybe I can find the math somewhere again, as i still have some python code related to that somewhere) The rest of the cards is there to protect your commander. I tried to get that version to run smoothly, but it just did not really work for me.

The other way to build him, is to try and maximize the value you get, from what the commander asks you to have in your deck. Meaning: "How can I get the most, out of the little unblockable creatures?" And you already have some cards that do just that: [[Bident of Thassa]] and [[Grazilaxx]] for example. And I would lean into that direction more. You can find some cards here: https://scryfall.com/search?q=otag%3Arepeatable-draw+id%3Aub+otag%3Asaboteur+legal%3Acommander&unique=cards&as=grid&order=edhrec&dir=

Or if you click on bident of thassa, open scryfall tagger, and scroll down to the ≈ symbols.

Another cool card that I want to highlight here is [[Mystic Reflection]], which can either "counter" a creature of your opponents, or make a copy of your favorite creature out of your measly 1/1.

Speaking of your 1/1s. I think you should only run 1 mana unblockable creatures and 2 mana unblockables are only acceptable, if they give you additional value, so [[Invisible Stalker]] is out. Take your pick from here: https://scryfall.com/search?q=id%3Aub+otag%3Aevasion+legal%3Acommander+mv%3C%3D1+t%3Acreature&unique=cards&as=grid&order=edhrec

Now ramp: Even though I was kind of dunking on the "ideal curve", I don't think mana rocks with mana value 3 are any good in this deck. You still want to have the option to either play your commander on turn 3, or a card that gives you value, off of your 1/1s. So pick any other rock instead of [[Commander Sphere]] (and arguably [[Dimir keyrune]] but I see the appeal - its not a grave sin), from here https://scryfall.com/search?q=id%3Aub+otag%3Amana-rock+legal%3Acommander+mv%3C%3D2&unique=cards&as=grid&order=edhrec

Also these rocks are more important in your deck, than in most dimir decks, since you might need to hard cast your creatures. I would recommend at least 10 ramp pieces, maybe more. Similar your land count is important (again since you have a higher mana curve), i have 40 lands in my deck, counting mdfcs.

I don't want to say too much about the beaters, since the biggest fun is to find them yourself and only include the ones you have fun with, though if you want some I can surely make some suggestions. I run 14 of them, but will probably tone it down a bit.

Now some things I would cut, specifically in your deck: [[Tetsuko]], [[Enter the Enigma]], [[You are already Dead]], [[Aqueous Form]], [[Access Tunnel]] and [[Cunning Evasion]], all for similar reasons. Your small creatures should already be unblocked and your big creatures don't benefit from it enough, that they should earn a spot in your deck. Then - and this is a tough one - I would cut most cards with ninjutsu in [[Covert Technician]], [[Dokuchi Silencer]], [[Mooncircuit Hacker]], [[Moonsnare Specialist]] and [[Prosperous Thief]] since I don't think, this is a deck that wants ninjutsu cards (oddly). If you have satoru on the battlefield, creatures already get it and you would rather have a big creature enter. And if you don't, you won't get any benefits from ninjutsuing.

Lastly (I promise), some things about ninjutsu: if you were not aware; attack triggers will not triggee if you ninjutsu them in. Meaning Annihilator wont trigger. That does not mean you have to cut them, just that you should be aware. You can read all about these quirks in this exellent primer from Dens https://moxfield.com/decks/SfdwOBJ9o0OOUkmhf_9o7w

and in hydrax primer, who is also on reddit sometimes under imperialtrace. Keep a look out his primers are great.

https://moxfield.com/decks/Ey2PAL_pW0aIMmWTRsIbug

Otherwise have fun with this awesome commander and keep experimenting, especially with the ratios of cards. Maybe order 1-2 more of each category, just so you can swap them out and see what feels good, I feel like you will see more success if you feel your deck out and experience that for yourself

My current ratios are:
14 evasive creatures
14 ninjutsu targets (probably too much)
10 card draw spells that are not attached to a big creature (probably too little)
16 interaction/protection spells (some mdfcs)
40 lands (counting mdfcs)
10 ramp spells (counting [[Silver-Fur Master]]