We are going to analyze each clubs of Chibi Yandere Complete Edition, their buffs and why you should pick them and stay in the long run.
There is 12 clubs in Chibi Yandere Complete Edition. Each one of them have unique effects.
I will present you a full list.
Science club
Active bonus for being a member: Reduces by 5 the maximum suspicion rate.
Free access to a 
Screwdriver (Loudness: 1; Power: 20~30; Speed: 0)
Club activities: Research to get access to an improved incinerator, a robot, a free jet-pack, hack electronic devices and to craft a love potion. You can also add poisoning without the use of a 
syringe or destroy evidences.
Why joining this club ?
Joining the science club will help you with your murder plans, thanks to the reduction of your suspicion and having access to multiple tools reducing the evidences of your murder. It's perfect for players who want to commit the "perfect" murder.
Sport club
Active bonus for being a member: +1 Speed
Free access to a 
Baseball bat (Loudness: 3; Power: 40~80; Speed: -1)
Club activities: Will increase permanently your Stamina or your speed or in Sport.
Why joining this club ?
Joining the sport club will help you getting more resistant and more athletic. It may help you in various situations like studying longer and depending less on food. This club may help you in the long run to have better statistics that could not be obtained and in the short term increase your Sport stats without having the need to study. Not necessarily the strongest, to join if your want to max out Sport very quickly in the begin of the game.
Drama club
Active bonus: +1 
Social interactions per day
Free access to a 
Magical Wand (Loudness: 3; Power: 20~40; Speed: )
Club activities: Rehearsals will help you to perform an act, act will give you money and reputation depending on the popularity of the subject chosen. You can also learn new skills like Improvisation, 
Stress management, 
Seductive,