Gareki - Prince of Tennis fanfic

In the world of Karneval, an eight-year little boy named Gareki was sold away as a slave by his parents. But, soon, the slave-trading ship he was on, was destroyed because of a heavy storm. As he woke up, Gareki found himself in a whole brand new world along with a gift. "Eh? system? What is that?" Join Aikawa Ryushi, alias Gareki, as he conquers the tennis with the help of the system.