World King, Mondaiji tachi ga Isekai Kara Kuru Sō Desu yo? Wiki

Kurma (World King or World Dragon) She is part of "Avatara". She made herself look young in order to participate in the "Second Sun Authority War". She calls herself "Kuu-Chan" in her human form and urges others to call her the same. First Debut is in the Last Embryo Volume 2

Wanmei Shijie (Perfect World)

Mondaiji-Tachi ga Isekai Kara Kuru Sō Desu yo? (Light Novel

Mondaiji-tachi ga isekai kara kuru soudesu yo:Volume 7 - Baka-Tsuki

Mondai-Ji-tachi ga Isekai Kara Kuru Sō Desu yo? (Light Novel

Review: Ichiban Ushiro no Daimaou (いちばんうしろの大魔王)

Problem Children Are Coming from Another World, Aren't They

Sakamaki Izayoi Mondaiji tachi ga Isekai Kara Kuru Sō Desu yo

Rin, Mondaiji tachi ga Isekai Kara Kuru Sō Desu yo? Wiki

Demon King of Confusion Mondaiji tachi ga Isekai Kara Kuru Sō