I Got 999 Level With One Cut

*As the girl with a weak personality, Even though her true name is Meiko Hasegawa she still like to be called Riko because of her friends always call her that. 
In this peaceful world She thought she would live a normal person until her time has come. 
Until one day (an extremely common day),She was Dead… 
Because of a cockroach she had transmigrated into the Isekai world. 
The world where the Dragons and gods exists… 
How could a high school girl survive in such dangerous world!？ 
「Ding! Welcome using the Ultimate Omnipotent Online Upgrading System」 
（Speechless…） 
OK, then…. 
The first thing - chop down the little feral pig with a kitchen knife for dinner. 
“Detected host killed Wild Boar x1, beginning to transmit experience. “ 
“Congratulations! You have leveled up. Current level: 2”
 “Congratulations! You have leveled up. Current level: 5.”
 “Congratulations! You have leveled up. Current level: 9.”
 “Congratulations! You have leveled up. Current level: 273….”
 Wow! Hold on, A little piggy could not have that much Experience point, right？
Just like that she had to step on the road of becoming The most powerful sorcerer… 
Now In this cure world ( May be for others…), What kind of adventures are waits for our Cute Riko？