They straight-up promoted Pochi to Nyaa as being designed by the guy who came up with offsetting in Puyo Puyo, too.
If you want to add to the family tree, there’s also Pnickies (Compile-developed, Capcom-published arcade puzzle game that barely made it to market) which Capcom themselves remixed into Super Puzzle Fighter II Turbo.
Nyoki Nyoki was a digital-only, Japan-only game released towards the end of the 3DS’ life and didn’t include online multiplayer, so very few people ever had the opportunity to properly play it, and the majority of the footage they released centred on beginner-friendly options and how it was designed for newcomers to easily go toe-to-toe with veterans, so it was difficult to gauge how deep the game might be… it’s very clearly based on Pochi to Nyaa, so I think it’d probably have legs, but who knows.
Niitani lives an extremely humble life these days: he lives in a tiny apartment and works part time cleaning up after old people at an assisted living facility; Nyoki Nyoki 3DS cost ¥10M, half of which came from a loan from Niitani’s parents and the other half from a government grant, and it apparently didn’t come close to recouping, so he’s been personally paying off his debts ever since.
He did attempt to crowdfund a Switch version a few years ago but the campaign failed, and in recent years he’s been pushing NFTs and talking about gambling his retirement funds on stocks/crypto—he claims publishers don’t want to back him any more because he’s in his 70s and they’re all paranoid that he’ll die of old age before they’re able to recoup, so I do have a little sympathy for him, but I also wish he’d just find an international publisher or someone willing to handle a second crowdfunding campaign for him so he could go out with some dignity.