Honoka

Holly (Honoka) first appeared in "Tag! We're It!" as Brock's tag battle partner.

At first, Holly did not show any interest in Brock, saying that she had no interest in "younger men," but after battling together with him, she formed an attraction to him, impressed by his battling skills. Later, in Glory Blaze, she seemed jealous that he was flirting with Nurse Joy. Later on, she was seen to have "heart-eyes" while watching Brock battle.

After Holly and Brock lost the battle against Ash and Paul, she couldn't help but feel responsible for the loss. Afterwards, she left without saying goodbye to him. Nurse Joy told Brock that she wanted to train more, so that she could become a better partner for Brock.

(Source: Bulbapedia, edited)