Appendix:FireRed and LeafGreen walkthrough/Section 6
To Fuschia (via the Cycling Road)
Going through the Cycling Road is the faster way to getting to Fuschia City. To begin, go west from Celadon City onto Route 16. Go through the Guard House, and one will be finding himself on the Cycling Road (you must have a bike for going through!). On this road, the player goes downhill, which means that the player's bike will move by itself without any action from the player. However, if you the player tries to go up the hill, he will be going very slowly. There are many Bikers that one can fight on this road, which takes up Routes 16 and 17. After a long bit of biking, you'll reach Route 18.
Go through the Guard House after reaching Route 18. A trainer on the second floor will trade you his Lickitung for your Golduck. Route 18 is real short. After a few steps, the player'll arrive at Fuschia City.
To Fuschia (via the walking route)
Some people may choose to do things the harder way. The other way to get to Fuschia is slower and longer. To begin, fly to Lavender Town. Go south onto Route 12. Go to the second floor of the Guard House, where a little girl will give you TM 27 - Return. For the rest of the route, the player will be battling fishermen. Two lovers are also available to battle in a two-on-two match.
Fuschia City
Fucshia City is the home of the Kanto Safari Zone, an area filled with capturable wild Pokémon. At first, one can visit the Move Deleter's house, which is located right next to the Pokémon Center, to delete an unwanted move. Visit the house next to the house with the mailbox for a Good Rod. The Safari Zone can be visited later. For now, we need to fight the gym leader of this city's gym.
Fuschia Gym
It's time to get the sixth badge in the Fuschia Gym. However, getting to the gym leader may not be very easy. The gym is filled with invisible walls. The player has to walk around and figure out which areas one can go through and which ones one can't. Start on the right side, with the trainers serving as markers. Although they are invisible, a close observer would see that white dots mark the outlines of the walls.
Soon, after trial and error or by getting around the dots, the player will reach Koga, the gym leader.
He has two lv. 37 Koffing, a lv. 39 Muk, and a lv. 43 Weezing. Psychic Pokemon will work best against Koga's Pokemon. After beating four tough Pokemon, Koga will award you with TM06 - Toxic and the Soul Badge. In order to leave, you must go through the walls again.
Now that you've defeated Koga, you're only two more badges away from eight! For now, put the thought of getting the last two badges away, because we need to go into the Safari Zone for some item searching.