话说在纽约市的下水道之中住着四只功夫高强的忍者龟,它们跟随着忍者师父—一只来自日本的超级大老鼠.一次偶然机会,它们救了一名正义的电视女记者,她也成为了唯一知道忍者龟藏身处的人....
作为《寒蝉鸣泣之时》DVD全9巻购入者特典的“猫杀篇”OVA动画。片头、片尾曲和“寒蝉鸣泣之时”动画（第一期）相同。 前原圭一和其他社团成员玩扑克牌游戏，规则是输家接受惩罚，穿着女仆装、泳装等在村里进行Cosplay游行。游戏结束后，大伙步行到雏见泽村郊外的谷河内。园崎魅音说起她幼年时有一回和伙伴们到采石场附近玩捉迷藏，不久即被一位突然出现的大叔催赶回家，后来伙伴A行踪不明，A的父亲驱车前往谷河内寻找，不料在回程的途中2人的汽车翻落山崖。有传言说他们是因为吸入了从连通地狱的洞穴渗漏出来的瘴气而中毒……
Not only is Marinette Ladybug, the superheroine that protects Paris from the attack of villains, but she’s also now the guardian of the Miraculous. This means that not only does she need to keep her identity hidden, but also the existence of these turbulent, magical creatures, the Kwamis! Marinette has a lot of pressure, not to mention her school and love life! Now she has less time and opportunities to tell Adrien her feelings... Marinette now has to redouble efforts to protect her secrets and Ladybug will have to become stronger to face an indomitable adversary: Shadow Moth, who can now fuse the Butterfly and Peacock Miraculous! Thankfully, Ladybug can count on Cat Noir and their new superhero allies!
