Mars in 5th house. 

So, lets see what Mars can do in 5th house without any conjunction or aspect from any other planet. 1st lets see what these 2 things represent -

Mars represents our will power, courage, ability to take actions, aggressive nature, anger, our fighting ability, brother, male friends, a boy friend for a girl, a soldier, an athlete and real estate etc.

5th house represents Creativity, Happiness, Hobbies, Children, Innovation, Sports, Movies, Stock Trading, Gambling and Betting, Education, Ancient Texts etc.

Mars in 5th house is natural position for someone in Sports. They can be great athlete and sports-person as 5th house is house of sports and creativity and Mars represents courage, will power and fighting ability. They may become dominating towards children and their romantic relationship may suffer due to anger and dominating nature. Even in matters of education, person would love to compete and dominate others by getting higher marks. So, natural Mars approach of dominance will show up in 5th house matters. 

From 5th house, Mars aspects the 8th house of Occult Science and Secrecy and Mars provides lots of courage to person to research into occult and secrets to know about it. 

Mars next aspect goes to 11th house of gains, earning and income, and these people are very dominating towards their gains. They want it to be more than their peers.  

Mars next aspect goes to 12th house of Spirituality and Foreign Lands, and here person feels fluctuations in his spiritual interests. . 

Hope this helps. Thanks,

Swami Premanand Bharti