I found the save file from the sagaoz.net website which has a massive collection of Japanese hentai game full save files. This particular link will lead you to the page for this game's save file:
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When it loads, do a quick search using the Ctrl+F shortcut and paste the Japanese title into the search bar to find the game. This game's name is ネトラレたママは好きですか?~教育ママと家庭教師~
Now for some odd reason I find there is a space after the ~ in Japanese titles, so if you don't find the game the first time you copy/paste, like it is with this game, you'll want to go back to the very first ~ you can find in the title and then add a space after it. Or you can simply do what I did before figuring out the whole space thing and back space one letter/symbol at a time until it finds the game, highlight the whole title and do a quick google search and check out any of the links to see if the cover picture of the game you've found via the search is the same as the game you want. Either way you go about it, find the game you're looking for and then click the link on the right side to get the save file.
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After that, you'll want to open up the readme file that comes with the save file using japanese local, I'd recommend using Local Emulator as it's the only way I know of how to run .txt files in Japanese. The text file will tell you where to place the save file and that can range anywhere from a folder in the documents, over in the app data folders, or even in a save folder found in the game's folder. This particular game's save file is located in the main folder, where the game's exe file is. If it was located elsewhere, you'll need to look for the Yen symbol ¥ which is what I'm assuming is the Japanese equivalent of the backslash \ in regards to computer folder structures or directories; I forget the appropriate term at the moment.
And if you're ever looking for another game's save file and want to see if it's on sagaoz.net, just do a google search like this: sagaoz.net
ネトラレたママは好きですか?~教育ママと家庭教師~ The only thing is you'll replace the bold/italicized letters/symbols with whatever the name of the game you're looking for.
Hope that makes sense and helps you out.