Yoshino Kobayashi is a thirteen-year-old girl who is famous for her skill in the battle board.
Yoshino is an arrogant and selfish girl who considers the game characters as nothing more than piles of data and a tool for her to learn new strategies for the battle board. However, Yoshino is often influenced by the memory of her deceased father, whom she loves so much for being very close to her. This causes her to sometimes show some care to Guile, such as giving him some food to eat. Later, when Yoshino's grandma finds out all Yoshino's horrible deeds towards Guile and her juniors, her grandma scolds her. After knowing that Yoshino's dad serves to limit Yoshino's cruelty towards Guile, Yoshino's grandma also corrects her way of acting because like the whole Kobayashi family, Yoshino is supposed to be a doctor when she grows up, and her personality is sure to hinder that. Yoshino eventually proves that she is a caring and strong-willed person, which fixes her friendship with Guile.
Combat Strategy Edit
Yoshino prefers overpowering the enemies with a strong attack while disregarding defense, and offense is preferred for defending. She doesn't have any healing elements in her arsenal.
Guile vs Shadow Cat Edit
As instructed by Guile, Yoshino swipes Genius, which enables him to quickly obliterate Shadow Cat with Ball Lightning.
Guile vs Snibgoblin Edit
By swiping Strengthen, Yoshino enables Guile to catch Snibgoblin's arm and throw the beast away with ease. This stuns Snibgoblin and gives Guile the chance to deal the killing blow.
Guile vs Draggy Edit
Seeing Draggy immobilizing Guile by biting his arm, Yoshino swipes Strengthen, which allows Guile to lift Draggy to the air with his bitten arm and perform a piledriver on the dragon (which doesn't happen because Guile doesn't really want to and Ari sees through his plan).
Guile vs Starky (1st form) Edit
At first, Yoshino swipes a Genius in hopes that Guile can severely injure Starky in a hit. However, Guile deliberately fires a misdirected wave of lightning, and Starky easily dodges it. Near the end, although Guile has sustained serious injuries, Yoshino swipes a Magnify because she is confident that Guile can still overpower Starky. With Draggy's help, this strategy works and Guile incapacitates Starky.
Yoshino was the champion of the 2020 Battle Board Tournament with Guile board. Due to her ability to predict a foe's next move, she earned the title 'Psychic Girl'. But she did not care because this skill actually came from her serious research about Battle Board via the Internet. Because all she wanted was just holding her championship as long as she could, she kept searching everything about Battle Board strategies all the time.
Yoshino actually wanted a Glenn board, but because whenever she saw Guile's picture she remembered about her deceased father, she ended up buying Guile board. But this led to an unpleasant consequence.
One night, when Yoshino was searching, something went wrong with her Internet connection. Angered, she cursed and was about to smack her modem, but when she lifted the object, she found a Chrono Cross chip there (implying that it had always been hidden under the modem). Curious, she inserted the chip into her Guile board, which led to the transformation of the board into a gadget.
When she picked up the gadget, she found a red arrow on the monitor pointing to the west - the window. She looked at the window, which was steamy. This induced her curiosity and she decided to check what was happening outside.
Outside, she found Guile standing under a tree, dozing. She approached him, and Guile mentioned that Yoshino's gadget and a Chrono Cross element were what that called him. This pissed Yoshino off to the very extreme as she could not summon a stronger character this way. However, she managed to control her outburst as she suddenly remembered her father, who often mentioned 'a masked magician with long lavender hair'. She decided to ask Guile why he was there, and after a pause, Guile said that he only wanted to be more powerful (which turned out to be a lie). Yoshino was not happy with that because she did not know how, but then, she thought of an idea. Yoshino and Guile made a promise: Yoshino helped Guile to find a way to be more powerful while Guile fought for her so that she could learn more tricks for the Battle Board. Despite sounding promising, Yoshino actually did not care about making Guile stronger for two reasons: she had no knowledge about how Guile could be stronger and she considered empowering a pathetic character like Guile was just a waste of time.
The next day, Yoshino and Guile began searching for a foe to practice on. They found Shadow Cat digging a mound of trash inside an alley. Guile surprised the beast with Lightning Rod, but seeing this, Yoshino complained as in the Chrono Cross game, a character had to launch successful physical attacks before being able to cast an element/tech/spell. Guile said that he did not understand what Yoshino said, which only annoyed Yoshino, who began complaining that she could not learn new tricks that way. But Guile managed to calm her down by telling her that she can vary her strategy with support elements.
Unfortunately, during the conversation, Shadow Cat regained composure and attacked Guile, digging its claws deep into Guile's right shoulder and disabled his right arm. Yoshino barked at Guile for being weak, but Guile told her to support him with a 'Genius' as he prepared for a powerful thunder spell, Ball Lightning. His plan succeeded, and Guile annihilated Shadow Cat with his spell combined with Genius.
After that, Yoshino saw a cloud of golden molecules and asked Guile about it. Guile explained that it was data, and it came from a dead being. He also said that it served like a food for him: absorbing it would heal his injuries and make him stronger. Yoshino told him to absorb it, and Guile did it.
But as Guile absorbed the data, a mysterious man in black named Chisiki Takashi overheard Guile saying "Loading data" and saw the mess in the alley. Chisiki warned Yoshino not to get too close to Guile because Guile was not a normal being. Yoshino and Guile did not mind too much about that warning.
It had yet to be revealed what happened after that, but it was often mentioned that Yoshino abused Guile out of her hatred towards Guile for 'stealing her chance to summon a strong character'. She left him to sleep outside (whether it rained or not, she didn't care), didn't give him anything to eat, threw him a pail of cold water if he overslept, forced him to fight even when he was tired and injured, and snapping at him whenever he is losing in a fight or showing weakness. However, she occasionally showed some care for Guile by giving him some food, and it was perhaps Yoshino's memory of her deceased father that affected her.