The entire written story was created by George Tasker (if you like this anime sex game’s story, please consider reading his other work!) as a choose-your-own-adventure game over 15 years ago. There may be some girls you’ve haven’t heard about in a long, long time or maybe even ever. KlonHad has kindly converted the game into HTML and added a few GIFs to spice it up, but there is otherwise nothing new. The passages are copied/pasted directly from the old CYOA.
Back to Secret Agent School is a light-hearted, goofy spy romp filled with sex. You can either play as a bumbling buffoon with a knack for sexually harassing your female co-workers or his sexy, sometimes naive, female partner. It is relatively short and there are very few options- you’re looking at a play-time of under an hour, maybe even 30 minutes.
I have to say, this was like playing an old retro-game and realizing that while it was innovative and fun at the time, you now want much more.