Asuka's shinobi heritage comes from her Grandfather Hanzo on her mother's side. Although her mother was a shinobi, her father was not. Originally, her father dreamed and was on the verge of becoming a successful lawyer, however he was charmed by Asuka's mother. Hanzo did not approve of their relationship, and the two constantly fought about it. Asuka's father loved her so much that he was willing to give up his dream of becoming a lawyer, as long as he could be with her.
According to him, he didn't need dreams or money if he could spend his life with her. Hanzo was so moved by his resolve and dedication that he could not bear to refuse his proposal, allowed them to get married and decided to open up a sushi shop with Asuka's father.
When Asuka was growing up, she had a reputation for getting into fights and beating up boys and girls alike, to which Hanzo told her she was an independent sword, without a compatible shield.
At some point, Asuka enlisted in Hanzo National Academy to follow Hanzo's footsteps and to understand the concept of being a sword and a shield.
During her first year, Asuka had some trouble keeping up with both Katsuragi and Ikaruga due to her clumsy nature, but she managed to push through and reached her second year with average scores.
Asuka, in her hurry to grab some futomaki rolls was rushing around town in search of something "big and thick", but nobody serves anything of that size other than her Grandfather.
While wandering around the shopping district she happens to come to the realization that big and large foods are in desperate need of attention. But while wondering how she can go about it, she happens to come across a flyer. She decides to enter the tournament in hopes of showing everyone how great large foods are.
Asuka finds Ikaruga and happily chats with her. But she soon changes her mind after asking Ikaruga how she likes "them". Ikaruga is stunned until Asuka reveals she was referring to food - much to her relief. However, Asuka gets angry and demands an answer. When it isn't the one she wanted, she prepares to cook off against Ikaruga, determined to leave her with a giant Futomaki before she takes off.
After the round concludes, Asuka shoves the giant Futomaki into her mouth. She ignores her dazed, muffled voice and heads off in order to take on her next opponent.
Asuka spots Homura but while she tries to take it seriously, she is interrupted by Asuka - who shoved the Futomaki roll in her mouth. Homura is annoyed and shoves her away, claiming her mouth isn't big enough to eat it. Asuka is startled that Homura may not agree with her, and Homura wonders if she has been put into a strange trance over her obsession.
Once again Asuka leaves someone stunned over the turn of events. She is happy that Homura is "accepting" of the roll, and Homura wonders if perhaps she may have actually been right. So she challenges Asuka by saying she loves them "Thick, Big, AND Hard". Her words go unnoticed by the determine Asuka though.
Asuka is shocked to find Daidōji waiting for her in the last round. She admits that she didn't think she would be into this, and Daidouji explains that she heard of Asuka's quest. Asuka is delighted that Daidoji is on her side, but ends up ticking her off after she claims Daidoji can't match her own love of such large things.
After defeating her, Asuka tiredly celebrates her win. Daidoji congratulates her for the win, but Asuka cuts it short so that she can eat something. So she insists everyone joins her for a Futomaki Party.
At the sushi shop, she reveals the large Futomaki that she got for her friends. They hesitate until she encourages them to just try it, then proceeds to shove the rolls into their mouths once more.
With relief, Asuka hopes that the world will open up to her desires to expand foods now, believing her friends to be "happy".
Asuka's Shinobi outfit strikingly resembles the uniforms from the To Love-Ru series and Ikkitousen series' Nanyo's school.
Asuka seems to not like her breasts being big and actually wishes they were smaller. (However, it is possible that she says this because of Katsuragi's perverted nature; believing that if her breasts were smaller, then Katsuragi wouldn't grope her.)