ケミーが人を喰べる！？
ユーフォーエックスと無事仲間になった
宝太郎たちの前に現れた新たなレベルナンバー10。
その名も「エックスレックス」！
しかし、エックスレックスには
なんと人間を食べてしまうという驚きの習性が。
放置はキケン。ガッチャに走るも
なぜそんなことをするのか、疑問を持つ宝太郎。
一方、エックスレックスを追う影がもう一つ。
それは、オカルトライターの間辺とその娘、爽。
父のことを想う爽に、自分を重ねるりんね。
しかしそこに、再び冥黒の三姉妹の魔の手が迫る…！
最強恐竜レベル10、その真意は一体！？
Kemmy can eat people! ? A new level number 10 appears in front of Houtarou and his friends who have successfully become friends with UFOX. Its name is “XX-Rex”! However, the X-Rex has a surprising habit of eating humans. Leaving it unattended is dangerous. Houtarou runs into Gotcha, but wonders why he would do such a thing. Meanwhile, there is another shadow chasing X-Rex. They are occult writer Manabe and his daughter, Sawa. Rinne begins to identify with Sou, who is thinking about her father. But then, the evil hand of the Three Dark Sisters approaches again...! The strongest dinosaur level 10, what is its true meaning? ?
