Coins are simple in High School Story. Your main goal should be to maximize the number of hangouts that you have. Especially go for the nerd hangouts which can earn up to 3,500 coins at a time, and jock hangouts, which can earn up to 2,000 coins at a time. Prep hangouts only earn up to 1,000 coins at a time, although they do accumulate coins much more quickly, so for active players these are the best ones.
Set the time ahead on your phone in order to skip ahead, which will enable you to be able to earn coins very quickly. This also allows you to cut down the waiting period for quests, so that you race through them faster. The quests are a great source of coins.
To earn free rings, connect the game to Facebook and start linking your Facebook friends with classmates in the game. The game won’t post on Facebook unless you hit the “share” button after you link someone to a character, so if you don’t want them to know that they have been linked, they never have to know. You can get rewards for up to 20 of your linked classmates.
Earn more books, AND more experience points, with the completion of quests. The faster you complete quests, the faster you earn experience points. Quests won’t earn you that many books compared to getting books via the classroom, but they do count for a semi decent number of them, enough to upgrade a few students who have not yet been upgraded.
To get more books, first, maximize the amount of classrooms that you have per experience level. Then, make sure that they always have an order runnning. Collect that order as soon as it finishes, so that you can get yet another order started. Keep the books flowing this way.
To get books MUCH more quickly than this, use the time lapse cheat to set the time ahead by however much time your current orders take to complete. Then go back to the game and collect the books that came in. Set the time back to normal, and then start another order. Repeat this as often as you like in order to earn massive amounts of books.