Blue is on cinnabar island and after you get 15 gym badges you can face him.
The 5th gym is the Fuchia city gym Gym leader Koga
The 7th Gym is on Cinnabar Island.
The final gym is the Viridian City Gym. Blue is the Gym leader.
His name is Blue. He will appear in the Gym after you beat all the other gym leaders. Once you beat the Cinnabar Gym, talk to Blue on Cinnabar Island. He will be the only person there. Then he will return to the Gym.
in saffron city gym and her name is Sabrina
The 6th gym is located in Fortree City.
go to the 5 gym
He is a Gym Leader.He's the Gym once you get to the kanto in the game.
The first gym is in pewter city.
You have to get the other seven Kanto gym badges, and then show those badges to Blue. Blue is on Cinnabar Island, and he will not leave to go to the Viridian City gym unless you show him the seven Kanto badges.
In Pokemon Blue, the fourth gym a player may battle is in Celadon City. One of the player's Pokemon must know the HM Cut in order to access the gym which is a Grass-type gym.
the last gym leader is Blue.When you go to the seventh gym leader Blaine you should see Blue and asks you if you have 7 badges then you beat Blaine and go to Blue and he says to meet him at his gym