Majime was a sales man for Genbu until Araki transferred him to the Dictionary Editorial Department. He is a bookworm and has a hard time expressing his own feelings, though he does make a conscious effort of learning how to. He fell in love with Kaguya at first sight when she came to her grandmother's house, although he had troubles telling her about his feelings and asked Nishioka for some advises.
Mitsuya Majime first appeared to help the heroes in order for themselves to get stronger just before the war started.
After the deaths of Kain and Thornheart and the beginning of the journey of Tekkadan from Mars, Mitsuya just reported to Wataru Kurenai that Majime himself is the father of Professor Kiryu.
Allies and Enemies
Allies: Hibiki Tachibana, Tsubasa Kazanari, Chris Yukine, Maria Cadenzavna Eve, Shirabe Tsukuyomi, Kirika Akatsuki, Miku Kohinata, Souji Tendou/Kamen Rider Kabuto, Arata Kagami/Kamen Rider Gatack, Ruuji Familon, Arashi (Zoids), Midori, Heero Yuy, Kira Yamato, Setsuna F. Seiei, Bugs Bunny, Marika Kato, Milinda Brantini, Sento Kiryu/Kamen Rider Build, Milinda Brantini, Dominic Toretto, Greg Heffley, Tsubomi Kido, Wade Owen Watts, Shouya Ishida, Hei (Darker than Black), Ryuga Banjou/Kamen Rider Cross-Z, Soichi Isurugi, Misora Isurugi, Sawa Takigawa, Eiji Hino/Kamen Rider OOO, Professor Kukui, Professor Burnet, Kouta Kazuraba/Kamen Rider Gaim, Kaito Kumon/Kamen Rider Baron, Mitsuzane Kureshima/Kamen Rider Ryugen, Takatora Kureshima/Kamen Rider Zangetsu/Zangetsu Shin, Suzuka Kamiki, Gas-House Gorillas, Kazumi Sawatari/Kamen Rider Grease, He Jin, Hyde Kido, Bastion Misawa, Horrid Henry, Mirei Mikagura, Etemon, Volcamon, Yūna Yūki, Mimori Tōgō, Fu Inubouzaki, Itsuki Inubouzaki, Karin Miyoshi, Sonoko Nogi, Hiroki Nagase, Masaru Ooyama/Akaba, Syuuya Aikawa/Aoba, Syoukichi Mihara/Kiba, Futaba Ichinose, Chitose Karasuma, Kenzo Tenma, Kudelia Aina Bernstein, Atra Mixta, Wataru Kurenai/Kamen Rider Kiva, Kivat-bat the 3rd, Kate Green, Gentoku Himuro/Night Rogue/Kamen Rider Rogue, Rinna Sawagami, Nariaki Utsumi, Akari Tsukimura, Leena Toros, Aila Jyrkiainen, Hester Shaw, Kouhei Araki, Jiro, Ramon, Riki, Leo Conrad , Sally Land, Seraphimon, Cherubimon (Good), Ophanimon, Guardian Eatos, Kuroto Dan/Kamen Rider Genm, Knight Unryuji, Rona Tsunomori, Rei Kiriyama
Enemies: Gunther Prozen, Thaddeus Valentine, Hajime Busuzima, Thornheart (deceased; killed by Milinda Brantini), Dr. Ellie Staple, Kain (RESTOL Special Rescue Squad) (deceased), Flinty McCallahan (deceased), Greta Hideg, Matori, Dr. Zager, Gozu (Pokemon), Mikie Okamine, Masakuni Mido, Jail Scaglietti, Gabby Jay, Alva, Kuroto Dan/Kamen Rider Genm (formerly), Rustal Elion, Carta Issue, Iok Kujan, Gallus Bauduin, Elek Falk, Iznario Fareed, Nemo Baklazan, Julieta Juris, Wolf Rocky, Knight Unryuji (formerly), Shia Kijima, Wilfrid Kijima, Saga Adou, Swartz, Uhr, Ora, Tid, Great New Empire