Let me clear this up for you.
Standard attacks only attack the person in front of you, generally. However, there are a few exceptions.
1. Some Characters (Earth Mains) have the option of attacking the entire row as their standard attack.
2. Some Ninja (Hinata) has a mystery that attracts any normal standard attack if they are in the front row.
3. Lightning Mains have the option of using "Lightning Assassination Sword", which attacks the person with the lowest HP on your team, instead of the person in the front. Some characters, like Playboy Sasuke, also have this option.
If, say, the lightning main snaked his way to Kisame and started a combo, then every one of your opponent's characters (assuming he has a decent team) would then proceed and chase at Kisame, following the original combo starter.
Mysteries work differently. If you use a mystery, it will go off on the character that you highlighted (you know, by clicking on them), as long as you are not on auto. If you ARE on Auto, the computer will, by default, attack the person on the opposing team that has the lowest HP.
Hope I helped. As a general rule of thumb, don't insult people who are just trying to help you, even if they are being a little condescending. It doesn't make people want to help you, especially when your original post was the thing that was unclear.