|Boldness||10 (5 for Natsuki)|
Yūko Yoshikawa is a main character in the series Hibike! Euphonium. A nice, friendly and cheerful person. She is shown to have good self-confident, high determination, and strong personality. She can openly and confidently show others what she is thinking through her action, her facial expression and her words.
- She admires, respects and cares for Kaori deeply to the point of fangirling. She often asks Kaori if she wants to go home together, and she holds her in high regard.*If someone hurts Kaori in any way she will get hostile and angry. She is also shown being by Kaori's side quite regularly.
- The reason she admires Kaori so much is because Kaori was the person who supported and encouraged her to stay in the band during Kitauji Concert Band Schism last year.
- Yūko also wants to make Kaori's "wishes" come true before graduating, like playing the solo-part even if it means hurting someone else.
- When Reina was given the trumpet solo, Yuuko became aggressive towards her out of protection for Kaori, whom she felt deserved it more.
- In some of the official arts, she is showing to be closer to Natsuki Nakagawa through being fed by her under the same cloth, and being hugged by her.
- In the pool, after viewing Kaori in a white swimsuit, she was astonished by her beauty and refers to her as an angel.
- In one of the episodes, she kissed Natsuki in the lips.
- She accepted Natsuki's harassment in love.