Jellyfish Can't Swim in the Night: Kim Anouk Mei Takanashi

 Member of the JELEE, she composes music for the group.  She became a fan of Kano Yamanouchi during her idol days after meeting her after an event. She found her thanks to a video of her playing the guitar ended up online and then joined JELEE.

My Instant Death Ability is So Overpowered, No One in This Other World Stands a Chance Against Me!: Sion

 Sion is the Sage responsible for the summoning of Yogiri's class to another world.

Over the moon for you: Aya Arisugawa (Season 2)

She is Kaname's older sister. She is a lazy ditz, but Kaname considers her on the "genius side" for her great learning capacity. In contrast to that, she usually misunderstands important things and gets really confused in the blink of an eye. Her favorite hobby is playing video games and she usually nags Kaname into playing with her.

If My Wife Becomes an Elementary School Student: Takae/Marika Shiraishi

 Takae the heroine. Keisuke's late wife. Although she had low blood pressure, she was a devoted person who would make lunch for Keisuke every morning, but on the other hand, she was very clear and forthright in expressing her opinions, which made Keisuke feel intimidated. She passed away in a traffic accident 10 years ago. She was reincarnated as "Marika Shiraishi" through reincarnation.

Marika Shiraishi, She grew up in a single-parent household and was neglected by her mother Chika at the Shiraishi household, but when she passed by the Niijima household, her memories of her previous life returned and she regained consciousness as "Takae Niijima", and she began to interact with the Niijima family. She not only speaks her mind openly in front of Keisuke and Mai, but also writes "magnolia" in beautiful handwriting when practicing calligraphy, and comments on her classmates' childish (or meaningless) fuss, and her friends from elementary school see her as having changed slightly from "Marika Shiraishi".

Later on, she temporarily loses her memories as Takae, and her personality reverts to that of an elementary school student. After visiting the grave, the temple priest points out to her that Keisuke is not reincarnated, but rather "possessed," with two personalities. Reincarnation is "a process of resetting everything, becoming a new life, and starting to learn." Marika had never met Keisuke and the others before, so as soon as her personality reverted, she saw Keisuke and the others and suddenly burst into tears in fear on the street, which led to the police being called, but after that, with Chika's understanding, Keisuke and the others began to interact as the "Shiraishi family."

Afterwards, Takae's personality reappears, but Takae is conflicted, knowing that she cannot continue like this forever. In the end, she is satisfied and passes away after seeing Keisuke give Yoshimi an engagement ring and propose to her (it was actually a lie) , and Takae's personality disappears completely.

Before Takae passed away, she left a letter for Chika and a notebook for Marika, detailing the events that had occurred while she had "taken over" her body.