3. Increase your chance to become student council
As seen in the previous post. You'll need to focus on your 
Social sciences statistics and 
Language statistics.
You also need to focus social interactions with your class mates. You need to increase your reputation or at least try to maintain it.
To help you, you should read 
Viper manga (available at the pawn shop 1800 yens or at the 
Book store when you have more than 80 
in Language.
Reading this manga give you the trait "
Charismatic" increasing your chance to get chosen by your classmates.
How classmates will pick you or someone else?
Here is the formula:
For you: Reputation+Current Opinion+the Charismatic Bonus
For opponents: Reputation*2+the Charismatic Bonus
Your goal is clear here, you need to have opponents with the lowest Reputation. It's randomize, if you're not lucky maybe avoid wasting your time and focus on other parts of the game and saving some bucks. Luckily, your classmates don't have very high reputation.
Here is the three most difficult students:
Sukubi Dubidu
Riku Soma
Koharu Hinata
In the easier side you'll have:
Daku Atsu
Juku Ren
Yaku Zaishi
Important, you must be at class during day 3 to participate at the elections. Check your calendar to see upcoming events.
The next you'll have the elections (and the results) and your first meeting as student council.
Note that you will be able in the long run to avoid bad proposals that are always against your profit . It will increase your reputation and will allow you to play more risky. The benefits are quite game changing but other ways to play may give you a huge lead. I will upload other strategies and explain them in detail. Maybe being hypocrites is not your thing, you want to be wild and don't care about consequences. Maybe you want to be a bit more sneaky and killing people without being noticed by the police with the "perfect crime". We will see more way to play and to win the game.