Clair has a long and unforgettable past that seems to be explained in the manga.
When she and
Lance were 10, the two got to raise their own Dratini. In addition, Lance got her
a
Horsea because it was her birthday and they decided to have a battle afterward. Clair wins pretty
easily the first time so their grandfather trains Lance after hearing his loss.
The next time they meet is when the two are 16. Lance has gotten
stronger and is prepared to challenge Clair again.
This time, though, he defeats her because his Dratini has evolved into a
Dragonair. After her defeat, Clair seeks
training immediately. Her grandfather does nothing but gives her a
Dragon Scale. Knowing that when her Seadra is exposed
to the item, she evolves into a
Kingdra. The morning after, the family calls up
Clair to become the new
Blackthorn City gym leader. She states that Lance is much better at that position,
but he chose to become the
League Champion instead. Clair in the end accepts her new role as gym leader.
Clair is the
granddaughter of the leader of the
Dragon Tamer Clan, the Master/Grandmaster. Both
Lance and Clair are capable battlers who also specialize Dragon-type Pokémon. Sometimes, they will come to the cave and visit their relative.
The Elder, as he is known in the English editions of
Pokémon Adventures manga, makes a visit with Clair in order to
train her to be stronger. He was later revealed to have invited
Drayden over to Blackthorn City in order to train
Iris for the same reason.
It was briefly stated in the anime that Liza and Clair were
childhood friends. When Liza met Ash, she knew he had a Charizard so she decided to ask him, Brock and
Misty if they would like to see the
Charicific Valley. She also looks after Ash's Charizard when he left
it there for training. She appeared for three episodes after this to help Clair stop the Dragonite from
destroying the Dragon's Den and later watches the gym battle between Clair and Ash for the
Rising Badge.