She is partnered to Hawkmon and as such is the first central DigiDestined to be partnered with an opposite sex Digimon, as Hawkmon is male. Yolei is a touch on the geeky side, stubborn, cheeky and impulsive. While she is somewhat loud and bold, she is very sincere and true to her feelings to the point where she is often unaware of others or how her feelings are affecting them. Yolei is compassionate and generous, but capable of being decisive and resourceful. She has odd tendencies to suddenly become depressed without explanation, but always finds the strength to come back and help her friends.
Yolei's most notable skill is her technical prowess; she can fix anything from a toaster oven to a computer. She helps her family in an Ai-Mart convenience store, Cody Hida and T.K. Takaishi live in. She works in it often and takes food from it to supply the group and their ever-hungry Digimon with. She has a crush on Ken Ichijouji and idolizes Mimi Tachikawa and Koushiro Izumi. She is apparently the youngest of four siblings: she has two sisters (high school-aged Momoe, junior high-aged Chizuru) and a brother (college-bound Mantarou).
Yolei's catchphrase when something goes right for her is "Perfecto!"
Digimon Adventure: Our War Game!Edit
She was among the kids who had indirectly helped the DigiDestined out in their fight with Diaboromon. As a result, she would eventually become a DigiDestined herself.
Digimon 02: First HalfEdit
She obtained her D-3, Hawkmon and the Digi-Egg of Love on her first week of her final year in Odaiba Elementary. On Golden Weekend, the main characters got a surprise visit from Mimi whom Yolei got along with well. When the Odaiba Elementary soccer team was to play a match against the team from Tamachi, Yolei was disappointed when it seemed Ken wouldn't show up but then he did. However, Yolei was shocked to learn that Ken was the Digimon Emperor. Later, when a Dark Spiraled Digitamamon attacked Mimi, Yolei lost her composure and began screaming at him. This outburst resulted in the manifestation of the Digi-Egg of Sincerity, which Yolei used to Armor Digivolve Hawkmon to Shurimon, who freed Digitamamon from the Spiral.
When the location of the Digimon Emperor’s base was discovered, the DigiDestined decided that they would have to stay in the Digital World until it was destroyed. Yolei covered up the fact that she was nervous with some ridiculously over-the-top eagerness, barking orders and rushing around, even managing to scale a Control Spire. When her over-eagerness lead to Hawkmon getting poisoned by Dokugumon, Yolei felt guilty about it. Hawkmon was alright about it as he preferred Yolei as she is.
Digimon 02: Hurricane Touchdown/Golden Armor EvolutionEdit
Getting a distress message from Kari, Yolei went to the United States with the other DigiDestined to help her and T.K. But on the way, they met Willis, a DigiDestined from Colorado, whose rogue Digimon partner (Kokomon) was the cause of it.
Digimon 02: Second HalfEdit
Davis thought it was a good idea to ask Ken to join their group. Yolei did not agree since she had seen Stingmon kill Thundermon at Ken’s command. However, when Mimi called on the new kids to help battle a Golemon, Yolei was forced to confront her feelings about Ken, which led to her accepting him. While searching for Gatomon’s lost power ring, she, Ken and Kari ended up in the Dark World. Upon finding the Dark Ocean, Kari lost her composure due to her last visit. This event was taken advantage of by Blossomon. It took Yolei's slap and harsh words to make the two girls see eye-to-eye, causing them to give their Digimon the power to DNA Digivolve.
At Christmas, Yolei, Sora and their Digimon were sent to Russia but they had no translator to help them cross the language barrier with the Russian DigiDestined. Yolei's attempts at charades eventually succeeded when she used the names of Russian foods to co-ordinate their attacks on the Flymon above the city. After going home, Yolei witnessed LadyDevimon's death by Silphymon, much to her horror. Yolei accepted it as they saved the current victims and any future victims of the sadistic Digimon.
At the Other World, Yolei was subjected to MaloMyotismon's illusion. Her desires were to be an only child and getting to eat all of the desserts. Hawkmon and ExVeemon broke her free of the illusion and she then joined with the other kids, who were in the process of breaking free of their illusions. Yolei used the power of the dream dimension against MaloMyotismon with Aquilamon, Shurimon, Halsemon and Silphymon appearing all at once.
Digimon 02: Diaboromon Strikes BackEdit
Three years after the events of Our War Game!, the evil Diaboromon resumed his reign of terror on the Internet. Yolei was trying on uniforms for Odaiba Jr. High when she was called by Izzy and was filled in on the situation. The Kuramon were bio-emerging via e-mail so while Tai, Matt and their Digimon entered cyberspace to battle Diaboromon once more, the others had to track down the Kuramon. Yolei and Kari found the first and caught it for Izzy to examine. When Davis learned that Kari, T.K. and their Digimon had gone to help their big brothers and Omnimon, he urged Yolei to open the gate for him so he could go to Kari. But Yolei made the gate too wide and the entire Kuramon swarm emerged from the gate before heading to Tokyo Harbor to assimilate into Armageddemon. Yolei was forced to watch the battle to follow until Imperialdramon destroyed the monster. Using her laptop, Yolei activated the cell phones of the crowd watching the battle, who then used them to capture the Kuramon, while the DigiDestined did the same with their Digivices, to send them all back to Izzy to take care of them.
During Book Three, Yolei accompanied several of the Digidestined to the tamer's universe. In the battle against Barbamon, she managed to Biomerge with Hawkmon to become Valkyrimon. She continues to be a valuable ally in battle and her relationship with Ken is a fairly stable one, even when her emotions aren't. Chiyo Suzume used her powers as the Demon of Seduction to force the girls to attack their boyfriends in Book Six. Yolei tried to smash Ken's head in with a fire extinguisher, but Wormmon managed to save his partner in time. Afterwards, she was so sorry for trying to harm her friends and boyfriend.
In Book Seven, she and Hawkmon had to flee from Rayleigh Thompson's forces after Rika was framed for the murder of the Prime Minister. When she saw armed forces storm the residence that Ken was hiding inside, she nearly lost it and charged in herself. Hawkmon and her friends were able to prevent her and Ken, Ryo, Cyberdramon, and Wormmon all came out alright. She fled to the park and later escaped to the Digital World, even though Rayleigh attempted to trap them at the park.