Yoshino is a Ptolemaic Army official and a villain and playable character in Metal Slug Attack.
Destroy The Tower
While training her soldiers, the Amadeus Syndicate deployed the Toschka Dalanue to attack them. The tower kills her soldiers, but Yoshino manages to take down the tower. Several Amadeus Robots then appear and self destruct in an attempt to kill her, but she is saved by Dragunov.
Yoshino battles a rare variant of the Martian Monoeye, a "Dark Monoeye". Accompanying it are Tar Man of different colours, who are blocking her efforts to stop it. However, Yoshino then receives help from a new member of the Ptolemaics, Caroline, the Ptolemaic Army's mechanic. Using a scaled model of the F502 Shooting Ray, Caroline rescues Yoshino and forces the Monoeye and its minions to retreat.
Kung Fu Guru
While Chunyan and Yoshino were making dumplings, Dragunov came in and informed them they were going for a raid on the Amadeus Syndicate headquarters. The three attack the building and confront Amadeus' AI copy of himself, not knowing it isn't him. They fire on it, but their attacks do nothing. The real Amadeus then reveals and tells them their attacks actually damaged the main computer, causing the AI to self destruct. The three Ptolemaics then flee the Amadeus building before they can be consumed by the explosion and return to base. Dragunov expresses frustration at how the mission was a failure, but Chunyan decides to make dumplings to cheer everyone up, which Dragunov and Yoshino decide to take part in as well.
Yoshino takes her apprentice Sho to a quiet area to train him, but Sho expresses discomfort at the new area they are training at and how Yoshino seems to be able able to read his mind. Yoshino tells Sho that he needs to be more confident and shouldn't have self-doubt. After they finish training, Yoshino tells Sho that she had Dragunov assign him a mission. Right as they are leaving, a meteorite crashes at their location and Schwarz Metzelei emerges from it. Schwarz asks the two if they are the "P.M. soldiers" she is searching for and Yoshino tells her that they are. Schwarz declares that the Ptolemaic Army has caused the Invaders too much trouble and that she has been sent to eliminate them, expressing delight at how she will get to eat more humans.
Yoshino tells Sho to take care of Schwarz and the weapon behind her before apparently abandoning him, much to Sho's shock. After Sho successfully uses his signature attack, "Air Rend", on Schwarz, and drives her off, Yoshino comes out of hiding and congratulates Sho, who is excited to have won against uneven odds for the first time. However, Sho then notices Yoshino's hand is clenched and asks her why before she punches him, telling him that he's still too young and that she's disappointed he did not notice her hiding, which Sho apologizes to her for.
United Front the 13th
As the Ptolemaic Army begins another United Front operation, Dragunov discusses Lucy being assigned to the Animal Squad with Yoshino. Yoshino states that she has never heard about her before, to which Dragunov tells her that when she came into the army, she and Caroline took care of her for a while.
While training Sho, Yoshino sneaks up on her pupil, scaring him. Yoshino then expresses disappointment that he pupil can't tell the difference between friendly and enemy contact, stating that he needs to train his body and mind. Yoshino sends him flying into the air, causing him to land in a nearby building. Dragunov later shows and asks Yoshino where Sho is, to which Yoshino points to the facility she flung him into. Dragunov recognizes the building as an Amadeus research facility Amadeus Syndicate and the two notice smoke coming from it, correctly taking it as a sign that Sho is fighting inside.
Because the Ptolemaic Army was short on supplies, Yoshino took part in an operation to gather more resources. The operation proved difficult, however, because of the Rebel Army. When the Ptolemaic Army fell under attack from the Rebel Army's Big Shiee, Yoshino and Dragunov led a mission to destroy it. After taking out the Rebel Army's initial defenses, Dragunov discovered Caroline had tagged along and tells Yoshino that Caroline is with them. Dragunov asks if they should send her back, but they find that her hovercraft has crashed. Thus, the two reluctantly allow Caroline to tag along.
While Dragunov stayed behind with Caroline, Yoshino scouted ahead. later discovered that the Rebel Army had allied with Abul Abbas and his Arabian Revolutionaries. She was spotted by Abul, but managed to defeat him. After being informed by Dragunov that their target is moving, Yoshino spares Abul and leaves to meet up with them, telling Abul that she will kill him if she sees him again. After rendezvousing with Dragunov and Caroline at the Rebel Army's Big Shiee, the two find Allen O' Neil is guarding it and decide to destroy it if they can't capture it. After destroying, the three are surprised when Allen O' Neil rises from the wreckage and shoots Dragunov. Yoshino then engages him while ordering Caroline to take Dragunov to safety. In the Secret Ending, Caroline presents Dragunov and Yoshino with the ShootingRay she just built.
The Dreams of the Prodigious Mechanic
After Caroline got in a fight with Dragunov over her disobeying orders to go inspect the Rebel Army's new Crablops, Yoshino found her, crying, and assured her they would get the Crablops for her. After an operation spearheaded by Caroline to defeat the Crablops proves a success, Yoshino speaks with Dragunov and wonders what Caroline will be like after the layoff.
Cloak of Darkness
After Dragunov allows Towa and Caroline to go a mission to steal the Tani Oh from the Rebel Army, Yoshino steps in and states that Towa seems like a nice, honest girl who has guts to steal from them, before noticing how Dragunov is wary of how the messenger and the commander-in-chief's instruct from the shadows.
After Caroline and Towa successfully acquire the Tani Oh, Dragunov and Yoshino discuss how playful the two are with it, finding it annoying, but note how the Tani Oh will greatly bolster their forces. Dragunov then notes that there have been more masked soldiers around their base recently and asks her to help her find Ptolemaios without being caught. Yoshino notes how unusual it is for Dragunov to breach military protocol but agrees to help her anyway. In the Secret Ending, Dragunov and Yoshino watched as Towa helped Caroline find some tools she misplaced, noting how well the two got along and how Towa was the second best mechanic in the army.
During a battle between the Ptolemaic Army and Rebel Army, Yoshino snuck up on Dragunov and some of her soldiers, only to reveal her identity by laughing. She then asks Dragunov if she has tracked down the "witch". After the battle, Yoshino discusses with Dragunov how Simon was experimented on by Mira, just as a soldier comes to bring more news to them.
Later, Dragunov and Yoshino are shown by Caroline the Rebel Army's Sergeant Drill, which was being used by Allen O' Neil. The two are eager to get revenge on Allen, but are stopped by Caroline, who comments that they are being reckless. Dragunov and Yoshino infiltrate the Rebel Army and are shown by Caroline the way to the Sergeant Drill. Dragunov sighs, prompting Yoshino to tell her that there's nothing to lose and everyone in the army is willing to protect her. Dragunov then recalls her memory of the time she first met Yoshino, when the two battled each other to a draw. Dragunov offered Yoshino a chance to join the Ptolemaic Army but Yoshino refused at first. Later, after deciding she had no where else to go, Yoshino took up Dragunov's offer and joined the Ptolemaics.
The three soon are faced with Allen O' Neil and Destrade. While Dragunov pursued Allen went to the Sergeant Drill, Yoshino fought Destrade and prevented her from intercepting Dragunov. After defeating Destrade, Yoshino arrives to back up Dragunov and Caroline against Allen. Before Allen can fight all three himself a soldier arrives and tells him that Morden has ordered an emergency council. Thus, Allen retreats and abandons the Sergeant Drill.
In the Secret Ending, while Dragunov was searching for a hidden laboratory, Yoshino approaches her and asks her to take a break to check up on the new hovercraft Caroline and Towa are building in the workshop. Dragunov at first refuses but after Yoshino insists as the two are using her money to build it, Dragunov agrees.
Out in the jungle, Yoshino trained her apprentice Sho is training with his master out in the jungles. However, after Yoshino performs an attack on him, Sho screams and states that the attack would have killed him if he got hit. Yoshino tells Sho that fear protects, but he must retaliate against his opponent or death will return again. Sho then says that he is unworthy of the secret skills but Yoshino tells him he is complaining. However, when Sho insists that he is earnest, Yoshino halts their training. She decides to tell Sho the story of who she was before she joined the Ptolemaic Army. Sho tells her he knows a part of it due to Caroline telling him while drunk.
Yoshino then narrates her past to him, how her village was attacked and destroyed by Arabian Army. Sho asks Yoshino why she likes training, and she tells him its a hobby of hers. They then resume their training. However, Sho detects enemy movement in the distance. Yoshino is impressed and sends him flying towards the enemy's position, causing him to land in the enemy camp. Sho at first attempts to leave, but after remembering that Yoshino can still hear him, he fights the soldiers and defeats them. Yoshino then arrives and criticize him for taking a breather and they resume training. Sho asks Yoshino for the rest of her story and Yoshino starts telling him of it again. While out on a mission, she heard her village was being attacked and rushed back to defend it, killing all enemies in her path. She confronts Abul, who is in the Drache Macha, and destroys the tank, leaving Abul at her mercy. However, before she can finish off Abul, Yoshino hears of soldiers having found a survivor rushes to Shizuka. Sho learns that Yoshino has been teaching him because she wants him to learn the secret skill. He is concerned he will put her in danger, but Yoshino tells him that she never used the technique and that it would be perfect for him. Continuing her story, Yoshino reveals how the village elder asked to be put down. Yoshino refused so the elder incapacitates her instead and let the Arabians gun them down. Shizuka later found the elder and believed that Yoshino had left them to die, declaring her a traitor.
The Arabians then find the ninja and Shizuka faces Sho, who tells her that she will not fight her, but ends up fighting her anyway.
Later, Yoshino talks with Dragunov about how she has taught Sho the secret skill, and that he is worthy of her pride. Dragunov tells her that she should say it to him in person. Now that she has taught him the skills, Yoshino can serve Dragunov without concern for her own life. Dragunov believed that she had sent her to her doom many times before; Yoshino believed that they weren't dangerous at all, and the two laugh.
Yoshino fought against the Red Goblin when he attacked the base. Seeing that the base was not that damaged, Yoshino realized that he must be there for Ptolemaios. She fought against him, but was ultimately defeated.
Yoshino and Sho were encountered by Mira and Damian as they were on their way to collect more Anima for a ritual to revive Ptolemaios. They attempt to fight the pair but are defeated, allowing them to make their way to the workshop.