Kenji Koiso

A 17-year-old second-year student at Kuonji High School in Tokyo. A member of the physics club, he is a shy and introverted science-oriented boy. He is gifted at mathematics and regrets failing the selection for Japan's Math Olympiad representative team. He planned to spend his summer vacation working a part-time job maintaining the network, but he is invited by his crush and senior, Natsuki Shinohara, to visit Ueda City in Nagano Prefecture. Eventually, he uses his mathematical talent as a weapon to face a global crisis.

Catchphrases:

• "Um..."

• "Please, let this work!"

• "I-if you're okay with me..."

• "According to my calculations, it should be like this!"

• "I can't give up yet...!"

Natsuki Shinohara

18 years old, the eldest daughter of the Shinohara family. The great-granddaughter of Sakae Jinnouchi and a popular figure at school in the kendo club. Kenji Koiso's senior, she is a bright and refreshing beauty who looks great in a white dress. She visits Ueda City, Nagano, to celebrate her great-grandmother Sakae's 90th birthday. To fulfill a promise to Sakae that she would "bring a fiancé next time," she asks Kenji to take a part-time job acting as her fiancé. While she appears reliable, she also has a bit of a ditzy side.

Catchphrases/Sample Lines:

• "Nice to meet you!"

• "Please, Kenji!"

• "It's okay, we'll manage somehow!"

• "Ahaha, was that how it was?"

• "Let's all do our best!"

Kazuma Ikezawa

13 years old, one of Sakae Jinnouchi's great-grandchildren. He appears to be a gloomy otaku boy who stays shut in his room, but he is actually the world champion of a fighting net game. In the digital world, he is a master controlling "King Kazma," a super player sponsored by global corporations. He has absolute confidence in his skills, but his attitude has led to him being bullied in the past. To master fighting games, he continues to train daily under the guidance of his "Master."

Catchphrases/Sample Lines:

• "Leave it to me."

• "Weak."

• "It's not over yet."

• "I won't lose."

• "Come on. I'll take you on."

Sakae Jinnouchi

90 years old. The 16th head of the Jinnouchi family, which has lasted for centuries since the Sengoku period, she is an elderly woman leading a large family spanning four generations. As she celebrates her 90th birthday, many relatives gather from all over to celebrate. She is trained in traditional martial arts and possesses a vitality and dignity that defies her age. Inheriting the spirit of ancestors who served their local community, she has a wide network in politics and business. She accepts Kenji Koiso as Natsuki's fiancé and leads the clan with strong leadership during the global crisis.

Catchphrases/Sample Lines:

• "Pull yourself together!"

• "Cherish your connections with people."

• "Leave it to me!"

• "I'm not losing to the young ones yet."

• "Times like these are exactly when we must join forces."

Mansuke Jinnouchi

70 years old, the second son of Sakae Jinnouchi. He runs a fishery business in a port in Niigata and is an active fisherman who goes out on his own boat. He is a physically tough man with master-level skills in Shorinji Kempo. He is also the "Master" who taught Shorinji Kempo to his grandson, Kazuma Ikezawa, through OZ. Experienced and reliable, he tempers Kazuma's fighting techniques and mental strength through rigorous training.

Catchphrases/Sample Lines:

• "Put some spirit into it!"

• "Training never ends!"

• "Learn it with your body!"

• "It's not over yet, not by a long shot!"

• "Strength isn't just about technique."

Wabisuke Jinnouchi

41 years old. The illegitimate child of the great-grandfather who was the previous head of the Jinnouchi family. He ran off with the family assets and was missing for 10 years, but suddenly returns for Sakae's 90th birthday. During his disappearance, he was apparently immersed in AI research in America. A free-spirited wanderer with a genius intellect and sharp insight. He is deeply connected to the AI "Love Machine" and is a key figure in the story's major incident. Furthermore, he is Natsuki's first love.

Catchphrases/Sample Lines:

• "Now things are getting interesting."

• "Don't be bound by common sense."

• "Well, it'll work out somehow."

• "Humans are truly fascinating."

• "Now, I wonder what will happen."

Takashi Sakuma

17 years old. Kenji Koiso's classmate and a member of the physics club at Kuonji High School. The physics club is commonly known as the "PC Club," and he works the OZ maintenance part-time job with Kenji in the clubroom. Knowledgeable about computers and networks, he supports the work related to OZ as Kenji's close friend.

Catchphrases/Sample Lines:

• "Hey, Kenji!"

• "Wait a sec, let me check!"

• "Alright, maintenance complete!"

• "This is getting really bad...!"

• "Anyway, let's find the cause!"