Wakaba

One of the students in the classroom that was caught in the explosion from the fight between the Demon Lord and Hero at the beginning of the story.

Description
Wakaba Hiiro was the "queen" of their school in terms of beauty according to her classmates. Due to this, she ends up a bit isolated and many people found it difficult to talk to her. She is also secretly a gamer and she doesn't have a positive relationship with her parents often relying on cup ramen or meal money that they leave her while they are out at work.

Due to her lifestyle, her athleticism is among the lowest in class. She was loner both inside of class and outside of school, always keeping to herself. This made her an easy target bullying by one of the most popular girls in class, Shinohara Mirei, now known as Feirune in the other world. After spending some time reflecting after her reincarnation, Feirune expressed remorse for her past action and wanted to make an apology to her. Ooshima Kanata, presently known as Kanatia, once made a half-hearted confession to her. It was implied he was already uninterested in the opposite sex back then, but he wanted to use the botched attempt to fit in better with the rest of the boys in class, intentionally choosing Wakaba to get rejected based on her personality and history of never dating anyone.

History
Filimøs, due to increasing pressure from Karnatia, reveals the Wakaba Hiiro did not survive the ordeal in the new world. This revelation shocked Shun and his friends, especially Feirune, who was hoping that there would be a chance to reconcile and ask for forgiveness. This major reveal shocks the group, showing that not everyone has had such privileged lives as them.

Throughout the series, there were numerous hints that implied that Wakaba Hiiro was the identity of Kumoko. This was later confirmed in the Elf Village Arc, when a seemingly alive and unscathed Wakaba made an appearance to Shun's group. This greatly shocked Filimøs and the rest of Shun's party.

Major spoilers from volume 9 of the Light Novel: It was later revealed that Kumoko was not actually the real Wakaba Hiiro. But took on her appearance and memories due to D's influence in the beginning of the story. "Wakaba Hiiro" was a false identity created by D, which she used to masquerade as a high school student, partly to escape and slack off from her responsibilities as a god and enjoy life on Earth.

One day, the class was struck by a mysterious explosion that killed everyone except Wakaba Hiiro. In reality, the explosion was the result of combined a magical attack from a previous Hero and Demon Lord to assassinate Wakaba, viewing her as the cause for their world's plight. Feeling responsible for her classmates and teacher dying in the crossfire, and thinking it would be fun, she collected their souls and reincarnated them.

However, all her classmates dying and being reincarnated would likely draw the attention of fellow gods, and Wakaba Hiiro not being amongst them would surely lead to D being discovered. Therefore, she decided to misdirect them by giving the piece of her soul that was Wakaba Hiiro, with all her memories of her time on Earth, to a spider that happened to be in the classroom at the time, resulting in the creation of Kumoko. Also, to make sure the other reincarnates wouldn't notice her absense, she messed with Filimøs' Student Roster skill by having it state that "Wakaba Hiiro" was dead.

After creating Kumoko by fusing the part of her soul that was Wakaba Hiiro with a spider, D reincarnated her in the Great Elroe Labyrinth and expected her to quickly die off, taking the evidence of D's time on earth with her. However, she instead continued to survive and take on an appearance that is a combination of Wakaba Hiiro and her spider form following her after evolving into an Arachne and Shiraori.

Kumoko who at that point of time taken a new name, Shiraori, was greatly displeased after learning her current existence and memories was built on a lie.