|Manga||Kin-iro Mosaic Volume 1|
|Anime||Kin-iro Mosaic Episode 1|
- "It doesn't really matter who wrote me this letter. I'd much prefer just being with you, Aya!!"
― Yōko says to Aya before opening her supposed "love letter"
Her school attire includes the same skirt and shoes as the others, but she wears light blue vest with buttons and a pair of white tube socks. Her summer uniform consists of a white buttoned shirt with a loose collar.
For casual occasions, Yōko normally wears less-feminine clothing than her friends, normally wearing a pair of shorts or pants on most occasions.
Energetic and fiery with a sense of determination, Yōko is athletic and carefree with average school marks. Despite this, she is actually very level-headed and one of the calmer members of the group. She is normally mature and keeps her priorities set straight, but for most part she can easily adapt to the antics of her friends; after expressing surprise or confusion by them.
She values cooperation between friends and is normally in high spirits. She appears to be particularly fond of Alice because of her cute appearance and personality, and at the same time, she enjoys teasing those she cares for due to their entertaining responses. She appears to have an interest in females, as she often remarks on various desires that would sound as though she approves of fanservice.
She has been friends with Aya and Shinobu since middle school, but during the latters time away in England, Yōko became closer with Aya. While she is generally smart outside of school and capable of noticing things, she is fairly dense towards Aya's feelings and constantly tugs on her weak points and can easily make her blush unintentionally. Yōko does, however, seem to care a great deal about Aya and worries about her if she seems down. At this point she does not appear to fully reciprocate Aya's feelings, although it is hinted she may be growing aware of them.
Yōko was seen as a surrogate big sister for Shino due to how responsible she was. They get along very well but remain blunt with one-another at times, but never with ill-will behind it. They aren't shown bonding as much as they did when they were younger, due to their newer relationships.
Yoko finds Alice very cute and she loves to bring it up. She is normally kind and compliments her often, but she still remains honest and will tell her the truth about thing or if she gets too worked up. In return, Alice will mock Yoko for not being very smart, but tries to use kind words when doing so.
Due to their similar personalities, she gets along very well with Karen. They both enjoy eating and generally share the same opinions, but while Yoko is usually calm or cool-headed, being with Karen causes her to become more lively and energetic.
After witnessing the two friends interact, Isami put Yoko in charge of being a temporary big sister for Shino if she couldn't be around. In return, she also decided to become a big sister to Yoko to compensate her lack of an older sibling. Yoko feels close to Isami and often agrees with her on things when it comes to Shino.
- Her last name is a portmanteau of "猪" (wild boar) and "熊" (bear).
- Her given name means "girl like the Sun."
- Her flower motif is the Hydrangea.
- According to Alice, she shows her canines (fanged teeth) when she lies.
- Main article: Yōko Inokuma/Image gallery.