2021年5月初,有中国大陆网友发现,神乐七奈发布的影片Cynical Night Plan疑似抄袭彩虹社成员梅丽莎·金莲花(日语:メリッサ・キンレンカ)的翻唱PV。亦有网友将二者影片合为一个影片去进行比较,通过对比两者影片发现其画面风格等方面非常相似。针对相关质疑,神乐七奈在bilibili开直播说明此事,承认存在抄袭情况,自己存在疏忽没有仔细审核,将私下与梅丽莎以及制作PV的工作人员说明此事并删除在b站发布的该影片。有观众提出神乐七奈也应在Twitter上向梅丽莎公开道歉。但神乐七奈表示,会和梅丽莎与相关人员私下表达歉意,Youtube上的相关影片将在和制作团队讨论后再决定是否删除,同时也说明了为何进行本次直播:
It was made apparent to me that the "Cynical Night Plan”video that I uploaded on the 14th of February was very similar to that of Melissa Kinrenka's.
I uploaded the video despite being unaware of its contents when it was delivered. and that's why the responsibility is entirely on me.
I would like to apologize to everyone involved for any inconvenience caused, which is why I've written this message.
I have also deleted the video, shortly after I made it private.
To Melissa's fans, I'm sorry for causing any kind of misunderstanding.
I'm sorry to all of you who like my videos, as well as to have disappointed all of you.
From now on. I will establish a teom to thoroughly check every video before I upload them.[註 5][21]
我在2月14日上传的“Cynical Night Plan”影片与梅丽莎·金莲花的影片非常相似,这一点是显而易见的。