Spoiler Alert: This wiki article contains details about future plot lines described in the manga. Do not proceed unless you want to be spoiled!
Yoshino Koiwai (小岩井 吉乃, Koiwai Yoshino) is one of the main characters and the servant of Aki Adagaki. She wanted to apologize to Masamune Makabe 8 years ago, hence why she's secretly aiding him.
Yoshino has short, light brown hair with a small braid to the side and two cream coloured adornments clipped on opposing sides in her hair, whilst her eyes are also brown. She also has noticeably big breasts that she doesn't seem to be aware of.
Personality
Generally around people, Yoshino acts shy and soft spoken. However, she is revealed to be very mean towards Masamune Makabe. When ordered by Aki, she does as she's told. Yoshino is able to hide her emotions and act perfectly fine, which is an advantage as she is helping Masamune - the "enemy" of her mistress - in getting revenge.
Yoshino admits she was jealous of the friendship between Masamune and Aki.
Plot
Childhood
Throughout Yoshino's childhood, she's been the only friend and maid of Aki. Although she seemed to be very loyal and obedient, during the time, Aki was very cruel towards her and since then she has held a grudge against it, hoping Aki would learn her lesson in the future.
Helping 'Piggy'
Trivia
The name 'Yoshino' means 'Respectful' or 'Good'.
It was revealed that Yoshino had disguised herself as
Yoshino cries after to have ruined Masamune's Friendship (Episode 38)
Aki eight years before, and rejected Masamune, giving him the nickname "piggy" or "tonsoku (pig's foot)" in the original Japanese.
It's possible that she may have had feelings for Makabe Masamune.
