The official promotional video for the How NOT to Summon a Demon Lord anime series drew attention after its content proved to be too lurid for underage viewers. Avex Pictures uploaded the video on YouTube in March but it has since been flagged with a content warning. The minute-long video is mostly still shots and action sequences, but it does contain one long shot of characters Rem Galleu and Shera L. Greenwood while nude.

Interestingly, the anime's longer promotional video uploaded on Avex Pictures' account in June doesn't have a content warning despite containing the same scene and far more sexually suggestive content.

The anime's official Twitter account shared a screenshot of the newly added content warning on Saturday and also pointed out the lack of a warning on the longer video.

The anime premiered on July 5 and Crunchyroll is streaming the anime worldwide outside of Asia, and Funimation is streaming anime in the United States, Canada, United Kingdom, Ireland, Australia, and New Zealand.

J-Novel Club is releasing the novel series in English, and it describes the story:

In the MMORPG Cross Reverie, Takuma Sakamoto is so powerful that he is lauded as the “Demon Lord” by other players. One day, he is summoned to another world – but with the same appearance he had in the game! There, he meets two girls who both proclaim themselves to be his Summoner. They had performed an Enslavement Ritual to turn him into their Summon... but that's when Takuma's passive ability "Magic Reflection" activated! Instead, it was the girls who had become enslaved! Though Takuma may have been the strongest Sorcerer there was, he had no idea how to talk with other people. That's when he makes his choice: to act based on his persona from the game! “Amazing? But of course... I am Diablo, the being known and feared as the Demon Lord!” So begins a tale of adventure with an earth-shakingly powerful Demon Lord (or at least someone who acts like one) taking on another world!

You can read Anime News Network's episode reviews of the series by Christopher Farris here.

Source: How NOT to Summon a Demon Lord's Twitter account via Otakomu