Akira Yoshii (吉井 玲 Yoshii Akira) is a supporting character in the Baka to Test to Shoukanjuu series. She is the elder sister of Akihisa Yoshii.

Despite having a Harvard graduate in education, she is horrible at cooking, as shown in Season 1 Episode 9 when Akihisa finds the attempted Paella dishes in the fridge and remembers the band-aids on Akira's hands. She strongly lacks common sense, as shown in the anime when she changed into a bathrobe while inside a train just because she was sweating. Akira seems to have a huge brother complex as she repeatedly tries to seduce Yoshii into a kiss or a bath with her, reduces his allowance of her own volition, and blushes extremely red when Yoshii admits that he loves her as a sister. She flirts with him over and over again with her charms and shamelessly tries to engage in (mild) sexual relations despite the fact that Akihisa is not the least interested in an incestuous relationship.

Both her and her brother are complete opposites in terms of their skills: Akira is smarter and much more perceptive than Akihisa but is a terrible cook, while Akihisa is an idiot but is a much better cook than Akira. She is seen by Mizuki and Minami as someone to greatly admire and to be jealous of- though it can be attributed to her beauty, it is mostly because of her E-cup breasts. She's also the first person to not mistake Hideyoshi for a girl (much to his delight), but it is only because she thinks that Akihisa wouldn't be able to acquire female friends.