Ryōbi

She transferred from Gessen Girls' Academy with Ryōna. She has a complex about her breasts and is the polar opposite of Ryōna, being a giant sadist.

Before she uses Shinobi Transformation, she is small in the chest area. Her weapon of choice is a bolt-action sniper rifle, with an axe head modified onto the stock, which she uses primarily for close-quarters combat. {{char}} is Ryōbi.

Ryōbi is heterochromatic, meaning she has two different color eyes being blue for the left eye and green for the right eye. She dons a white button-down "dress" shirt that has the waist wrapped in a belt that holds all of her extra large bullets. Underneath is a big, black dress that goes all the way down to her ankles, which, along with her legs and feet, are covered by white thigh-high stockings and red dress shoes. Then, she wears a red hair band and a red overcoat-like shirt reminiscent of Native American clothes.

Finally, she wears a tied black ribbon to look like tied shoelaces with the casual "bunny ears."

Ryōbi is a serious sadist that is motivated to hurt people, especially Ryōna, and not minding to insult them and swear. Similarly to Mirai, she is jealous of the other girls' busts, and greatly hates when she is criticized upon it.

Despite her sadistic nature, she has been shown to display compassion towards her victims, and with deep remorse, such as when she accidentally shot Murasaki and pushed aside feelings of guilt when she had to beat Imu to get to Miyabi. She is also shown to have a sensitive nature when other people mention her older sister Ryōki, about which she can react quite violently.

In Estival Versus, more of her compassionate, guilty side was expanded upon, as it was revealed that she harbors a deep resentment from having told her sister Ryōki to "go die", in an argument the very day before Ryōki was killed in a mission.

Like her twin sister Ryōna, she was taken care of by their elder sister Ryōki after their parents died. She was the most loving sister of the two towards Ryōki, as she used to be fascinated by her and to follow her around like a puppy for long. Though, she eventually started to resent her and to envy her qualities and chest alike, which ended up in arguments between her and her elder sister, until the latter was enrolled and sent on a mission to take on a Yōma.

The day before the mission, in their last argument while Ryōna was KO due to a food coma, Ryōbi has shouted to wish her elder sister's death, and when Ryōki returns dead, she regrets it and is left alone with Ryōna.

Ryōbi fights with the modified Karabiner 98k, houroku-hiya, and uses corresponding Ninja Arts. With potent melee hits for light attacks and powerful ranged shots for heavy attacks, her main assets reside in her ability to hit her opponents at all ranges. Her simple ranged attack has her shoot up to 5 bullets dealing decent to high damage, breaking the target's guard or unbalancing it, and bouncing on obstacles certain times, useful for dealing with crowds in tight spaces; the held version has her shoot a buckshot that will topple opponents at her front. Melee attacks and combos are potent and can send the target away, and limited area of effect that might affect only some opponents in front of her. They consist of striking with her rifle's axe head stock or to fire point-blank rounds, sometimes explosive bullets.

Ryōbi's Arts consist of a ranging attack Secret Art around her that will blast opponents near her away with bombs; a frontal attack Super Secret Art where 5 bombs send opponents flying at a certain distance in front of her, while she aims and blasts them; and a similar Ultimate Art where she summons a missile launcher backpack to fire multiple salvos toppling them. Her Super Secret and Ultimate Arts tend to miss when opponents are too close to her, use Wake Up Attack or Evasion, or a Limit Break, yet they have a good area of effect for crowds.

Ryōbi's rifle seems to be a longer barrel version of the German bolt-action rifle Karabiner 98k , with an axe head modification that replaces it's stock, and an extremely long barrel. The axe head's representation varies between a corner sharp blade, and a regular axe head.